diff --git a/packages/flutter/lib/src/material/chip_theme.dart b/packages/flutter/lib/src/material/chip_theme.dart
index 777439e889..38b636315a 100644
--- a/packages/flutter/lib/src/material/chip_theme.dart
+++ b/packages/flutter/lib/src/material/chip_theme.dart
@@ -360,17 +360,7 @@ class ChipThemeData extends Diagnosticable {
   ///
   /// The arguments must not be null.
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   static ChipThemeData lerp(ChipThemeData a, ChipThemeData b, double t) {
     assert(t != null);
     if (a == null && b == null)
diff --git a/packages/flutter/lib/src/material/slider_theme.dart b/packages/flutter/lib/src/material/slider_theme.dart
index 085cda8d7e..4560710ae7 100644
--- a/packages/flutter/lib/src/material/slider_theme.dart
+++ b/packages/flutter/lib/src/material/slider_theme.dart
@@ -391,17 +391,7 @@ class SliderThemeData extends Diagnosticable {
   ///
   /// The arguments must not be null.
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   static SliderThemeData lerp(SliderThemeData a, SliderThemeData b, double t) {
     assert(a != null);
     assert(b != null);
diff --git a/packages/flutter/lib/src/material/tab_bar_theme.dart b/packages/flutter/lib/src/material/tab_bar_theme.dart
index 8a6455ba08..eeec4e1179 100644
--- a/packages/flutter/lib/src/material/tab_bar_theme.dart
+++ b/packages/flutter/lib/src/material/tab_bar_theme.dart
@@ -61,6 +61,8 @@ class TabBarTheme extends Diagnosticable {
 
   /// Linearly interpolate between two tab bar themes.
   ///
+  /// The arguments must not be null.
+  ///
   /// {@macro flutter.material.themeData.lerp}
   static TabBarTheme lerp(TabBarTheme a, TabBarTheme b, double t) {
     assert(a != null);
diff --git a/packages/flutter/lib/src/material/theme_data.dart b/packages/flutter/lib/src/material/theme_data.dart
index ee10b0266a..2f99e5c610 100644
--- a/packages/flutter/lib/src/material/theme_data.dart
+++ b/packages/flutter/lib/src/material/theme_data.dart
@@ -730,8 +730,6 @@ class ThemeData extends Diagnosticable {
   /// Linearly interpolate between two themes.
   ///
   /// {@template flutter.material.themeData.lerp}
-  /// The arguments must not be null.
-  ///
   /// The `t` argument represents position on the timeline, with 0.0 meaning
   /// that the interpolation has not started, returning `a` (or something
   /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
diff --git a/packages/flutter/lib/src/material/typography.dart b/packages/flutter/lib/src/material/typography.dart
index f8e69371e5..29349bdcc5 100644
--- a/packages/flutter/lib/src/material/typography.dart
+++ b/packages/flutter/lib/src/material/typography.dart
@@ -361,17 +361,7 @@ class TextTheme extends Diagnosticable {
   ///
   /// The arguments must not be null.
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   static TextTheme lerp(TextTheme a, TextTheme b, double t) {
     assert(a != null);
     assert(b != null);
diff --git a/packages/flutter/lib/src/painting/alignment.dart b/packages/flutter/lib/src/painting/alignment.dart
index efa2883b40..671855df36 100644
--- a/packages/flutter/lib/src/painting/alignment.dart
+++ b/packages/flutter/lib/src/painting/alignment.dart
@@ -85,17 +85,7 @@ abstract class AlignmentGeometry {
   /// representing a combination of both is returned. That object can be turned
   /// into a concrete [Alignment] using [resolve].
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   static AlignmentGeometry lerp(AlignmentGeometry a, AlignmentGeometry b, double t) {
     assert(t != null);
     if (a == null && b == null)
@@ -334,17 +324,7 @@ class Alignment extends AlignmentGeometry {
   ///
   /// If either is null, this function interpolates from [Alignment.center].
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   static Alignment lerp(Alignment a, Alignment b, double t) {
     assert(t != null);
     if (a == null && b == null)
@@ -525,17 +505,7 @@ class AlignmentDirectional extends AlignmentGeometry {
   ///
   /// If either is null, this function interpolates from [AlignmentDirectional.center].
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   static AlignmentDirectional lerp(AlignmentDirectional a, AlignmentDirectional b, double t) {
     assert(t != null);
     if (a == null && b == null)
diff --git a/packages/flutter/lib/src/painting/border_radius.dart b/packages/flutter/lib/src/painting/border_radius.dart
index ef244f91f1..ed16d30888 100644
--- a/packages/flutter/lib/src/painting/border_radius.dart
+++ b/packages/flutter/lib/src/painting/border_radius.dart
@@ -127,17 +127,7 @@ abstract class BorderRadiusGeometry {
   /// representing a combination of both is returned. That object can be turned
   /// into a concrete [BorderRadius] using [resolve].
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   static BorderRadiusGeometry lerp(BorderRadiusGeometry a, BorderRadiusGeometry b, double t) {
     assert(t != null);
     if (a == null && b == null)
@@ -481,17 +471,7 @@ class BorderRadius extends BorderRadiusGeometry {
   ///
   /// If either is null, this function interpolates from [BorderRadius.zero].
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   static BorderRadius lerp(BorderRadius a, BorderRadius b, double t) {
     assert(t != null);
     if (a == null && b == null)
@@ -708,17 +688,7 @@ class BorderRadiusDirectional extends BorderRadiusGeometry {
   ///
   /// If either is null, this function interpolates from [BorderRadiusDirectional.zero].
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   static BorderRadiusDirectional lerp(BorderRadiusDirectional a, BorderRadiusDirectional b, double t) {
     assert(t != null);
     if (a == null && b == null)
diff --git a/packages/flutter/lib/src/painting/borders.dart b/packages/flutter/lib/src/painting/borders.dart
index 99e61a54b7..8cf8181535 100644
--- a/packages/flutter/lib/src/painting/borders.dart
+++ b/packages/flutter/lib/src/painting/borders.dart
@@ -198,17 +198,7 @@ class BorderSide {
   ///
   /// The arguments must not be null.
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   static BorderSide lerp(BorderSide a, BorderSide b, double t) {
     assert(a != null);
     assert(b != null);
@@ -414,17 +404,7 @@ abstract class ShapeBorder {
   /// function instead. If both return null, it returns `a` before `t=0.5`
   /// and `b` after `t=0.5`.
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   static ShapeBorder lerp(ShapeBorder a, ShapeBorder b, double t) {
     assert(t != null);
     ShapeBorder result;
diff --git a/packages/flutter/lib/src/painting/box_border.dart b/packages/flutter/lib/src/painting/box_border.dart
index 76daa9a238..82f7d29220 100644
--- a/packages/flutter/lib/src/painting/box_border.dart
+++ b/packages/flutter/lib/src/painting/box_border.dart
@@ -98,17 +98,7 @@ abstract class BoxBorder extends ShapeBorder {
   /// For a more flexible approach, consider [ShapeBorder.lerp], which would
   /// instead [add] the two sets of sides and interpolate them simultaneously.
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   static BoxBorder lerp(BoxBorder a, BoxBorder b, double t) {
     assert(t != null);
     if ((a is Border || a == null) && (b is Border || b == null))
@@ -431,17 +421,7 @@ class Border extends BoxBorder {
   /// If a border is null, it is treated as having four [BorderSide.none]
   /// borders.
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   static Border lerp(Border a, Border b, double t) {
     assert(t != null);
     if (a == null && b == null)
@@ -731,17 +711,7 @@ class BorderDirectional extends BoxBorder {
   /// If a border is null, it is treated as having four [BorderSide.none]
   /// borders.
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   static BorderDirectional lerp(BorderDirectional a, BorderDirectional b, double t) {
     assert(t != null);
     if (a == null && b == null)
diff --git a/packages/flutter/lib/src/painting/box_decoration.dart b/packages/flutter/lib/src/painting/box_decoration.dart
index c3f0166579..e461f7b2df 100644
--- a/packages/flutter/lib/src/painting/box_decoration.dart
+++ b/packages/flutter/lib/src/painting/box_decoration.dart
@@ -216,17 +216,7 @@ class BoxDecoration extends Decoration {
   /// unmodified. Otherwise, the values are computed by interpolating the
   /// properties appropriately.
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   ///
   /// See also:
   ///
diff --git a/packages/flutter/lib/src/painting/box_shadow.dart b/packages/flutter/lib/src/painting/box_shadow.dart
index dce0c53580..44d8e1e986 100644
--- a/packages/flutter/lib/src/painting/box_shadow.dart
+++ b/packages/flutter/lib/src/painting/box_shadow.dart
@@ -94,17 +94,7 @@ class BoxShadow {
   /// a box shadow that matches the other box shadow in color but has a zero
   /// offset and a zero blurRadius.
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   static BoxShadow lerp(BoxShadow a, BoxShadow b, double t) {
     assert(t != null);
     if (a == null && b == null)
@@ -125,17 +115,7 @@ class BoxShadow {
   ///
   /// If the lists differ in length, excess items are lerped with null.
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   static List<BoxShadow> lerpList(List<BoxShadow> a, List<BoxShadow> b, double t) {
     assert(t != null);
     if (a == null && b == null)
diff --git a/packages/flutter/lib/src/painting/colors.dart b/packages/flutter/lib/src/painting/colors.dart
index d0ccd83e96..d735428092 100644
--- a/packages/flutter/lib/src/painting/colors.dart
+++ b/packages/flutter/lib/src/painting/colors.dart
@@ -194,19 +194,9 @@ class HSVColor {
   /// that will interpolate from a transparent red and cycle through the hues to
   /// match the target color, regardless of what that color's hue is.
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
+  /// {@macro flutter.material.themeData.lerp}
   ///
   /// Values outside of the valid range for each channel will be clamped.
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
   static HSVColor lerp(HSVColor a, HSVColor b, double t) {
     assert(t != null);
     if (a == null && b == null)
diff --git a/packages/flutter/lib/src/painting/decoration.dart b/packages/flutter/lib/src/painting/decoration.dart
index 0c12dddada..9c90f67a24 100644
--- a/packages/flutter/lib/src/painting/decoration.dart
+++ b/packages/flutter/lib/src/painting/decoration.dart
@@ -124,17 +124,7 @@ abstract class Decoration extends Diagnosticable {
   /// respectively to find a solution. If the two values can't directly be
   /// interpolated, then the interpolation is done via null (at `t == 0.5`).
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   static Decoration lerp(Decoration a, Decoration b, double t) {
     assert(t != null);
     if (a == null && b == null)
diff --git a/packages/flutter/lib/src/painting/edge_insets.dart b/packages/flutter/lib/src/painting/edge_insets.dart
index 66c1458141..afa7672180 100644
--- a/packages/flutter/lib/src/painting/edge_insets.dart
+++ b/packages/flutter/lib/src/painting/edge_insets.dart
@@ -190,17 +190,7 @@ abstract class EdgeInsetsGeometry {
   /// representing a combination of both is returned. That object can be turned
   /// into a concrete [EdgeInsets] using [resolve].
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   static EdgeInsetsGeometry lerp(EdgeInsetsGeometry a, EdgeInsetsGeometry b, double t) {
     assert(t != null);
     if (a == null && b == null)
@@ -556,17 +546,7 @@ class EdgeInsets extends EdgeInsetsGeometry {
   ///
   /// If either is null, this function interpolates from [EdgeInsets.zero].
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   static EdgeInsets lerp(EdgeInsets a, EdgeInsets b, double t) {
     assert(t != null);
     if (a == null && b == null)
@@ -790,17 +770,7 @@ class EdgeInsetsDirectional extends EdgeInsetsGeometry {
   /// (either [EdgeInsets] or [EdgeInsetsDirectional]), consider the
   /// [EdgeInsetsGeometry.lerp] static method.
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   static EdgeInsetsDirectional lerp(EdgeInsetsDirectional a, EdgeInsetsDirectional b, double t) {
     assert(t != null);
     if (a == null && b == null)
diff --git a/packages/flutter/lib/src/painting/flutter_logo.dart b/packages/flutter/lib/src/painting/flutter_logo.dart
index 3732102195..e9505b6101 100644
--- a/packages/flutter/lib/src/painting/flutter_logo.dart
+++ b/packages/flutter/lib/src/painting/flutter_logo.dart
@@ -127,17 +127,7 @@ class FlutterLogoDecoration extends Decoration {
   /// non-null value. If one of the values is null, then the result is obtained
   /// by scaling the other value's opacity and [margin].
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   ///
   /// See also:
   ///
diff --git a/packages/flutter/lib/src/painting/fractional_offset.dart b/packages/flutter/lib/src/painting/fractional_offset.dart
index dfa3b26378..a751e74f12 100644
--- a/packages/flutter/lib/src/painting/fractional_offset.dart
+++ b/packages/flutter/lib/src/painting/fractional_offset.dart
@@ -178,17 +178,7 @@ class FractionalOffset extends Alignment {
   ///
   /// If either is null, this function interpolates from [FractionalOffset.center].
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   static FractionalOffset lerp(FractionalOffset a, FractionalOffset b, double t) {
     assert(t != null);
     if (a == null && b == null)
diff --git a/packages/flutter/lib/src/painting/gradient.dart b/packages/flutter/lib/src/painting/gradient.dart
index df4ed65cf4..1b4217a02f 100644
--- a/packages/flutter/lib/src/painting/gradient.dart
+++ b/packages/flutter/lib/src/painting/gradient.dart
@@ -185,17 +185,7 @@ abstract class Gradient {
   /// function instead. If both return null, it returns `a` before `t == 0.5`
   /// and `b` after `t == 0.5`.
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   static Gradient lerp(Gradient a, Gradient b, double t) {
     assert(t != null);
     Gradient result;
diff --git a/packages/flutter/lib/src/painting/shape_decoration.dart b/packages/flutter/lib/src/painting/shape_decoration.dart
index 8ded26719c..ab7b352c15 100644
--- a/packages/flutter/lib/src/painting/shape_decoration.dart
+++ b/packages/flutter/lib/src/painting/shape_decoration.dart
@@ -204,17 +204,7 @@ class ShapeDecoration extends Decoration {
   /// fields are all null (including the [shape], which cannot normally be
   /// null).
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   ///
   /// See also:
   ///
diff --git a/packages/flutter/lib/src/painting/text_style.dart b/packages/flutter/lib/src/painting/text_style.dart
index 32f4d334f9..88da5cc6c9 100644
--- a/packages/flutter/lib/src/painting/text_style.dart
+++ b/packages/flutter/lib/src/painting/text_style.dart
@@ -560,17 +560,7 @@ class TextStyle extends Diagnosticable {
   ///
   /// This will not work well if the styles don't set the same fields.
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   ///
   /// If [foreground] is specified on either of `a` or `b`, both will be treated
   /// as if they have a [foreground] paint (creating a new [Paint] if necessary
diff --git a/packages/flutter/lib/src/rendering/box.dart b/packages/flutter/lib/src/rendering/box.dart
index 9f52c73199..a3dac1a311 100644
--- a/packages/flutter/lib/src/rendering/box.dart
+++ b/packages/flutter/lib/src/rendering/box.dart
@@ -449,17 +449,7 @@ class BoxConstraints extends Constraints {
   /// If either is null, this function interpolates from a [BoxConstraints]
   /// object whose fields are all set to 0.0.
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   static BoxConstraints lerp(BoxConstraints a, BoxConstraints b, double t) {
     assert(t != null);
     if (a == null && b == null)
diff --git a/packages/flutter/lib/src/rendering/stack.dart b/packages/flutter/lib/src/rendering/stack.dart
index 23f73e7ce2..9b1d7e11ad 100644
--- a/packages/flutter/lib/src/rendering/stack.dart
+++ b/packages/flutter/lib/src/rendering/stack.dart
@@ -131,17 +131,7 @@ class RelativeRect {
   ///
   /// If either rect is null, this function interpolates from [RelativeRect.fill].
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   static RelativeRect lerp(RelativeRect a, RelativeRect b, double t) {
     assert(t != null);
     if (a == null && b == null)
diff --git a/packages/flutter/lib/src/rendering/table_border.dart b/packages/flutter/lib/src/rendering/table_border.dart
index a6f42e412e..f30ea6552e 100644
--- a/packages/flutter/lib/src/rendering/table_border.dart
+++ b/packages/flutter/lib/src/rendering/table_border.dart
@@ -147,17 +147,7 @@ class TableBorder {
   /// If a border is null, it is treated as having only [BorderSide.none]
   /// borders.
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   static TableBorder lerp(TableBorder a, TableBorder b, double t) {
     assert(t != null);
     if (a == null && b == null)
diff --git a/packages/flutter/lib/src/widgets/icon_theme_data.dart b/packages/flutter/lib/src/widgets/icon_theme_data.dart
index 75d02f7851..57585d3530 100644
--- a/packages/flutter/lib/src/widgets/icon_theme_data.dart
+++ b/packages/flutter/lib/src/widgets/icon_theme_data.dart
@@ -68,17 +68,7 @@ class IconThemeData extends Diagnosticable {
 
   /// Linearly interpolate between two icon theme data objects.
   ///
-  /// The `t` argument represents position on the timeline, with 0.0 meaning
-  /// that the interpolation has not started, returning `a` (or something
-  /// equivalent to `a`), 1.0 meaning that the interpolation has finished,
-  /// returning `b` (or something equivalent to `b`), and values in between
-  /// meaning that the interpolation is at the relevant point on the timeline
-  /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and
-  /// 1.0, so negative values and values greater than 1.0 are valid (and can
-  /// easily be generated by curves such as [Curves.elasticInOut]).
-  ///
-  /// Values for `t` are usually obtained from an [Animation<double>], such as
-  /// an [AnimationController].
+  /// {@macro flutter.material.themeData.lerp}
   static IconThemeData lerp(IconThemeData a, IconThemeData b, double t) {
     assert(t != null);
     return IconThemeData(