diff --git a/SharedTests/GeometryTests.cs b/SharedTests/GeometryTests.cs
index 4ae36f2..7db8a79 100644
--- a/SharedTests/GeometryTests.cs
+++ b/SharedTests/GeometryTests.cs
@@ -5,6 +5,41 @@ using System;
 namespace SemiColinGames.Tests {
   [TestClass]
   public class GeometryTests {
+
+    public void AssertVectorsAreEqual(Vector2 v1, Vector2 v2) {
+      Assert.AreEqual(v1.X, v2.X, 1e-5);
+      Assert.AreEqual(v1.Y, v2.Y, 1e-5);
+    }
+
+    [TestMethod]
+    public void TestVector2Rotate() {
+      Vector2 v = new Vector2(10, 0);
+      AssertVectorsAreEqual(new Vector2(10, 0), v.Rotate(FMath.DegToRad(0)));
+      AssertVectorsAreEqual(new Vector2(0, 10), v.Rotate(FMath.DegToRad(90)));
+      AssertVectorsAreEqual(new Vector2(-10, 0), v.Rotate(FMath.DegToRad(180)));
+      AssertVectorsAreEqual(new Vector2(0, -10), v.Rotate(FMath.DegToRad(270)));
+      AssertVectorsAreEqual(new Vector2(10, 0), v.Rotate(FMath.DegToRad(360)));
+      AssertVectorsAreEqual(new Vector2(0, 10), v.Rotate(FMath.DegToRad(450)));
+
+      AssertVectorsAreEqual(new Vector2(0, -10), v.Rotate(FMath.DegToRad(-90)));
+      AssertVectorsAreEqual(new Vector2(-10, 0), v.Rotate(FMath.DegToRad(-180)));
+      AssertVectorsAreEqual(new Vector2(0, 10), v.Rotate(FMath.DegToRad(-270)));
+      AssertVectorsAreEqual(new Vector2(10, 0), v.Rotate(FMath.DegToRad(-360)));
+      AssertVectorsAreEqual(new Vector2(0, -10), v.Rotate(FMath.DegToRad(-450)));
+
+      AssertVectorsAreEqual(new Vector2(7.0710678f, 7.0710678f), v.Rotate(FMath.DegToRad(45)));
+      AssertVectorsAreEqual(new Vector2(8.6602540f, 5f), v.Rotate(FMath.DegToRad(30)));
+      AssertVectorsAreEqual(new Vector2(5f, 8.6602540f), v.Rotate(FMath.DegToRad(60)));
+      AssertVectorsAreEqual(new Vector2(-5f, 8.6602540f), v.Rotate(FMath.DegToRad(120)));
+      AssertVectorsAreEqual(new Vector2(-8.6602540f, 5f), v.Rotate(FMath.DegToRad(150)));
+
+      AssertVectorsAreEqual(new Vector2(7.0710678f, -7.0710678f), v.Rotate(FMath.DegToRad(-45)));
+      AssertVectorsAreEqual(new Vector2(8.6602540f, -5f), v.Rotate(FMath.DegToRad(-30)));
+      AssertVectorsAreEqual(new Vector2(5f, -8.6602540f), v.Rotate(FMath.DegToRad(-60)));
+      AssertVectorsAreEqual(new Vector2(-5f, -8.6602540f), v.Rotate(FMath.DegToRad(-120)));
+      AssertVectorsAreEqual(new Vector2(-8.6602540f, -5f), v.Rotate(FMath.DegToRad(-150)));
+    }
+
     [TestMethod]
     public void TestIntersectSegmentNotColliding() {
       AABB box = new AABB(new Vector2(0, 0), new Vector2(8, 8));