diff --git a/src/ImageSharp/Common/Helpers/ImageMaths.cs b/src/ImageSharp/Common/Helpers/ImageMaths.cs
index 45556741e6..c0c8e07e6f 100644
--- a/src/ImageSharp/Common/Helpers/ImageMaths.cs
+++ b/src/ImageSharp/Common/Helpers/ImageMaths.cs
@@ -134,7 +134,7 @@ namespace SixLabors.ImageSharp
         /// Converts degrees to radians
         /// </summary>
         [MethodImpl(InliningOptions.ShortMethod)]
-        public static float ToRadian(float degrees)
+        public static float DegreesToRadians(float degrees)
         {
             return degrees * ((float)Math.PI / 180f);
         }
diff --git a/src/ImageSharp/Processing/AffineTransformBuilder.cs b/src/ImageSharp/Processing/AffineTransformBuilder.cs
index cd66272b42..1f26d079d4 100644
--- a/src/ImageSharp/Processing/AffineTransformBuilder.cs
+++ b/src/ImageSharp/Processing/AffineTransformBuilder.cs
@@ -42,37 +42,38 @@ namespace SixLabors.ImageSharp.Processing
         /// </summary>
         internal Size Size => this.sourceRectangle.Size;
 
+
         /// <summary>
-        /// Prepends a centered rotation matrix using the given rotation in degrees.
+        /// Prepends a centered rotation matrix using the given rotation in radians.
         /// </summary>
-        /// <param name="degrees">The amount of rotation, in degrees.</param>
+        /// <param name="radians">The amount of rotation, in radians.</param>
         /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
-        public AffineTransformBuilder PrependRotationDegrees(float degrees)
-            => this.PrependMatrix(TransformUtils.CreateRotationMatrixDegrees(degrees, this.Size));
+        public AffineTransformBuilder PrependCenteredRotationRadians(float radians)
+            => this.PrependMatrix(TransformUtils.CreateRotationMatrixRadians(radians, this.Size));
 
         /// <summary>
-        /// Prepends a centered rotation matrix using the given rotation in radians.
+        /// Appends a centered rotation matrix using the given rotation in radians.
         /// </summary>
         /// <param name="radians">The amount of rotation, in radians.</param>
         /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
-        public AffineTransformBuilder PrependRotationRadians(float radians)
-            => this.PrependMatrix(TransformUtils.CreateRotationMatrixRadians(radians, this.Size));
+        public AffineTransformBuilder AppendCenteredRotationRadians(float radians)
+            => this.AppendMatrix(TransformUtils.CreateRotationMatrixRadians(radians, this.Size));
 
         /// <summary>
-        /// Appends a centered rotation matrix using the given rotation in degrees.
+        /// Prepends a centered rotation matrix using the given rotation in degrees.
         /// </summary>
         /// <param name="degrees">The amount of rotation, in degrees.</param>
         /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
-        public AffineTransformBuilder AppendRotationDegrees(float degrees)
-            => this.AppendRotationRadians(ImageMaths.ToRadian(degrees));
+        public AffineTransformBuilder PrependCenteredRotationDegrees(float degrees)
+            => this.PrependCenteredRotationRadians(ImageMaths.DegreesToRadians(degrees));
 
         /// <summary>
-        /// Appends a centered rotation matrix using the given rotation in radians.
+        /// Appends a centered rotation matrix using the given rotation in degrees.
         /// </summary>
-        /// <param name="radians">The amount of rotation, in radians.</param>
+        /// <param name="degrees">The amount of rotation, in degrees.</param>
         /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
-        public AffineTransformBuilder AppendRotationRadians(float radians)
-            => this.AppendMatrix(TransformUtils.CreateRotationMatrixRadians(radians, this.Size));
+        public AffineTransformBuilder AppendCenteredRotationDegrees(float degrees)
+            => this.AppendCenteredRotationRadians(ImageMaths.DegreesToRadians(degrees));
 
         /// <summary>
         /// Prepends a scale matrix from the given uniform scale.
diff --git a/src/ImageSharp/Processing/ProjectiveTransformBuilder.cs b/src/ImageSharp/Processing/ProjectiveTransformBuilder.cs
index 6c5fb46259..58c02108ac 100644
--- a/src/ImageSharp/Processing/ProjectiveTransformBuilder.cs
+++ b/src/ImageSharp/Processing/ProjectiveTransformBuilder.cs
@@ -35,7 +35,7 @@ namespace SixLabors.ImageSharp.Processing
             Guard.MustBeGreaterThan(sourceRectangle.Height, 0, nameof(sourceRectangle));
 
             this.sourceRectangle = sourceRectangle;
-        } 
+        }
 
         /// <summary>
         /// Gets the source image size.
@@ -63,16 +63,44 @@ namespace SixLabors.ImageSharp.Processing
         public ProjectiveTransformBuilder AppendTaperMatrix(TaperSide side, TaperCorner corner, float fraction)
             => this.AppendMatrix(TransformUtils.CreateTaperMatrix(this.Size, side, corner, fraction));
 
-        public void AppendRotationRadians(float radians)
+        /// <summary>
+        /// Prepends a centered rotation matrix using the given rotation in radians.
+        /// </summary>
+        /// <param name="radians">The amount of rotation, in radians.</param>
+        /// <returns>The <see cref="ProjectiveTransformBuilder"/>.</returns>
+        public ProjectiveTransformBuilder PrependCenteredRotationRadians(float radians)
         {
-            throw new System.NotImplementedException();
+            var m = new Matrix4x4(TransformUtils.CreateRotationMatrixRadians(radians, this.Size));
+            return this.PrependMatrix(m);
         }
 
-        public void PrependRotationRadians(float radians)
+        /// <summary>
+        /// Appends a centered rotation matrix using the given rotation in radians.
+        /// </summary>
+        /// <param name="radians">The amount of rotation, in radians.</param>
+        /// <returns>The <see cref="ProjectiveTransformBuilder"/>.</returns>
+        public ProjectiveTransformBuilder AppendCenteredRotationRadians(float radians)
         {
-            throw new System.NotImplementedException();
+            var m = new Matrix4x4(TransformUtils.CreateRotationMatrixRadians(radians, this.Size));
+            return this.AppendMatrix(m);
         }
 
+        /// <summary>
+        /// Prepends a centered rotation matrix using the given rotation in degrees.
+        /// </summary>
+        /// <param name="degrees">The amount of rotation, in degrees.</param>
+        /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
+        public ProjectiveTransformBuilder PrependCenteredRotationDegrees(float degrees)
+            => this.PrependCenteredRotationRadians(ImageMaths.DegreesToRadians(degrees));
+
+        /// <summary>
+        /// Appends a centered rotation matrix using the given rotation in degrees.
+        /// </summary>
+        /// <param name="degrees">The amount of rotation, in degrees.</param>
+        /// <returns>The <see cref="AffineTransformBuilder"/>.</returns>
+        public ProjectiveTransformBuilder AppendCenteredRotationDegrees(float degrees)
+            => this.AppendCenteredRotationRadians(ImageMaths.DegreesToRadians(degrees));
+
         /// <summary>
         /// Prepends a scale matrix from the given uniform scale.
         /// </summary>
diff --git a/tests/ImageSharp.Tests/Drawing/DrawImageTest.cs b/tests/ImageSharp.Tests/Drawing/DrawImageTest.cs
index a29342ad46..2f89236544 100644
--- a/tests/ImageSharp.Tests/Drawing/DrawImageTest.cs
+++ b/tests/ImageSharp.Tests/Drawing/DrawImageTest.cs
@@ -74,7 +74,7 @@ namespace SixLabors.ImageSharp.Tests
             using (var blend = Image.Load<TPixel>(TestFile.Create(TestImages.Bmp.Car).Bytes))
             {
                 AffineTransformBuilder builder = new AffineTransformBuilder(blend.Size())
-                    .AppendRotationDegrees(45F)
+                    .AppendCenteredRotationDegrees(45F)
                     .AppendScale(new SizeF(.25F, .25F))
                     .AppendTranslation(new PointF(10, 10));
 
diff --git a/tests/ImageSharp.Tests/Processing/Transforms/AffineTransformBuilderTests.cs b/tests/ImageSharp.Tests/Processing/Transforms/AffineTransformBuilderTests.cs
index 639f4b46fa..2a43e56e70 100644
--- a/tests/ImageSharp.Tests/Processing/Transforms/AffineTransformBuilderTests.cs
+++ b/tests/ImageSharp.Tests/Processing/Transforms/AffineTransformBuilderTests.cs
@@ -38,11 +38,11 @@ namespace SixLabors.ImageSharp.Tests.Processing.Transforms
 
         protected override void AppendTranslation(AffineTransformBuilder builder, PointF translate) => builder.AppendTranslation(translate);
         protected override void AppendScale(AffineTransformBuilder builder, SizeF scale) => builder.AppendScale(scale);
-        protected override void AppendRotationRadians(AffineTransformBuilder builder, float radians) => builder.AppendRotationRadians(radians);
+        protected override void AppendRotationRadians(AffineTransformBuilder builder, float radians) => builder.AppendCenteredRotationRadians(radians);
 
         protected override void PrependTranslation(AffineTransformBuilder builder, PointF translate) => builder.PrependTranslation(translate);
         protected override void PrependScale(AffineTransformBuilder builder, SizeF scale) => builder.PrependScale(scale);
-        protected override void PrependRotationRadians(AffineTransformBuilder builder, float radians) => builder.PrependRotationRadians(radians);
+        protected override void PrependRotationRadians(AffineTransformBuilder builder, float radians) => builder.PrependCenteredRotationRadians(radians);
 
         protected override Vector2 Execute(
             AffineTransformBuilder builder,
diff --git a/tests/ImageSharp.Tests/Processing/Transforms/AffineTransformTests.cs b/tests/ImageSharp.Tests/Processing/Transforms/AffineTransformTests.cs
index e78bb2c6d9..f86db5641f 100644
--- a/tests/ImageSharp.Tests/Processing/Transforms/AffineTransformTests.cs
+++ b/tests/ImageSharp.Tests/Processing/Transforms/AffineTransformTests.cs
@@ -80,7 +80,7 @@ namespace SixLabors.ImageSharp.Tests.Processing.Transforms
             using (Image<TPixel> image = provider.GetImage())
             {
                 AffineTransformBuilder builder = new AffineTransformBuilder(image.Size())
-                    .AppendRotationDegrees(30);
+                    .AppendCenteredRotationDegrees(30);
 
                 image.Mutate(c => c.Transform(builder, resampler));
                 image.DebugSave(provider, resamplerName);
@@ -102,7 +102,7 @@ namespace SixLabors.ImageSharp.Tests.Processing.Transforms
             {
                 image.DebugSave(provider, $"_original");
                 AffineTransformBuilder builder = new AffineTransformBuilder(image.Size())
-                    .AppendRotationDegrees(angleDeg)
+                    .AppendCenteredRotationDegrees(angleDeg)
                     .AppendScale(new SizeF(sx, sy))
                     .AppendTranslation(new PointF(tx, ty));
 
@@ -124,7 +124,7 @@ namespace SixLabors.ImageSharp.Tests.Processing.Transforms
             using (Image<TPixel> image = provider.GetImage())
             {
                 AffineTransformBuilder builder = new AffineTransformBuilder(image.Size())
-                    .AppendRotationDegrees(angleDeg)
+                    .AppendCenteredRotationDegrees(angleDeg)
                     .AppendScale(new SizeF(s, s));
 
                 image.Mutate(i => i.Transform(builder, KnownResamplers.Bicubic));
@@ -197,7 +197,7 @@ namespace SixLabors.ImageSharp.Tests.Processing.Transforms
             using (Image<TPixel> image = provider.GetImage())
             {
                 AffineTransformBuilder builder = new AffineTransformBuilder(image.Size())
-                    .AppendRotationDegrees(50)
+                    .AppendCenteredRotationDegrees(50)
                     .AppendScale(new SizeF(.6F, .6F));
 
                 image.Mutate(i => i.Transform(builder, sampler));
diff --git a/tests/ImageSharp.Tests/Processing/Transforms/ProjectiveTransformBuilderTests.cs b/tests/ImageSharp.Tests/Processing/Transforms/ProjectiveTransformBuilderTests.cs
index 0d9bd301dc..f467bed40c 100644
--- a/tests/ImageSharp.Tests/Processing/Transforms/ProjectiveTransformBuilderTests.cs
+++ b/tests/ImageSharp.Tests/Processing/Transforms/ProjectiveTransformBuilderTests.cs
@@ -34,13 +34,14 @@ namespace SixLabors.ImageSharp.Tests.Processing.Transforms
                 var builder = new ProjectiveTransformBuilder(new Rectangle(Point.Empty, s));
             });
         }
+
         protected override void AppendTranslation(ProjectiveTransformBuilder builder, PointF translate) => builder.AppendTranslation(translate);
         protected override void AppendScale(ProjectiveTransformBuilder builder, SizeF scale) => builder.AppendScale(scale);
-        protected override void AppendRotationRadians(ProjectiveTransformBuilder builder, float radians) => builder.AppendRotationRadians(radians);
+        protected override void AppendRotationRadians(ProjectiveTransformBuilder builder, float radians) => builder.AppendCenteredRotationRadians(radians);
 
         protected override void PrependTranslation(ProjectiveTransformBuilder builder, PointF translate) => builder.PrependTranslation(translate);
         protected override void PrependScale(ProjectiveTransformBuilder builder, SizeF scale) => builder.PrependScale(scale);
-        protected override void PrependRotationRadians(ProjectiveTransformBuilder builder, float radians) => builder.PrependRotationRadians(radians);
+        protected override void PrependRotationRadians(ProjectiveTransformBuilder builder, float radians) => builder.PrependCenteredRotationRadians(radians);
 
         protected override Vector2 Execute(
             ProjectiveTransformBuilder builder,
diff --git a/tests/ImageSharp.Tests/Processing/Transforms/TransformBuilderTestBase.cs b/tests/ImageSharp.Tests/Processing/Transforms/TransformBuilderTestBase.cs
index d109387cc4..3f259c9aa2 100644
--- a/tests/ImageSharp.Tests/Processing/Transforms/TransformBuilderTestBase.cs
+++ b/tests/ImageSharp.Tests/Processing/Transforms/TransformBuilderTestBase.cs
@@ -142,7 +142,7 @@ namespace SixLabors.ImageSharp.Tests.Processing.Transforms
         protected abstract void PrependRotationRadians(TBuilder builder, float radians);
 
         protected virtual void AppendRotationDegrees(TBuilder builder, float degrees) =>
-            this.AppendRotationRadians(builder, ImageMaths.ToRadian(degrees));
+            this.AppendRotationRadians(builder, ImageMaths.DegreesToRadians(degrees));
 
         protected abstract Vector2 Execute(TBuilder builder, Rectangle rectangle, Vector2 sourcePoint);