diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9fe0261..372b7c0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -43,6 +43,7 @@ else()
         "test/Vector3_test.cc"
         "test/Quaternion_test.cc"
         "test/Matrix_test.cc"
+        "test/Polar_test.cc"
         "test/Spherical_test.cc"
     )
     target_link_libraries(
diff --git a/Polar.cpp b/Polar.cpp
index aa28e9a..2ad451c 100644
--- a/Polar.cpp
+++ b/Polar.cpp
@@ -19,6 +19,13 @@ Polar::Polar(float newAngle, float newDistance) {
   }
 }
 
+Polar::Polar(Vector2 v) {
+  angle = Vector2::SignedAngle(
+      Vector2::forward,
+      v); // atan2(v.x, sqrt(v.z * v.z + v.y * v.y)) * Angle::Rad2Deg;
+  distance = v.magnitude();
+}
+
 const Polar Polar::zero = Polar(0, 0);
 
 float Polar::Distance(const Polar &v1, const Polar &v2) {
diff --git a/Polar.h b/Polar.h
index cbb161f..48d9f17 100644
--- a/Polar.h
+++ b/Polar.h
@@ -5,13 +5,15 @@
 #ifndef POLAR_H
 #define POLAR_H
 
+struct Vector2;
+
 /// <summary>
 /// A polar vector
 /// </summary>
 /// This will use the polar coordinate system consisting of a angle from a
 /// reference direction and a distance.
 struct Polar {
- public:
+public:
   /// <summary>
   /// The angle in degrees, clockwise rotation
   /// </summary>
@@ -34,6 +36,8 @@ struct Polar {
   /// <param name="distance">The distance in meters</param>
   Polar(float angle, float distance);
 
+  Polar(Vector2 v);
+
   /// <summary>
   /// A polar vector with zero degrees and distance
   /// </summary>
@@ -51,14 +55,14 @@ struct Polar {
   /// </summary>
   /// <param name="v">The vector to subtract from this vector</param>
   /// <returns>The result of the subtraction</returns>
-  Polar operator-(const Polar& v) const;
+  Polar operator-(const Polar &v) const;
 
   /// <summary>
   /// Add another polar vector to this polar vector
   /// </summary>
   /// <param name="v">The vector to add</param>
   /// <returns>The result of adding the vector</returns>
-  Polar operator+(const Polar& v) const;
+  Polar operator+(const Polar &v) const;
 
   /// <summary>
   /// Scale the vector uniformly up
@@ -76,7 +80,7 @@ struct Polar {
   /// <returns>The scaled vector</returns>
   /// This operation will scale the distance of the vector. The angle will be
   /// unaffected.
-  Polar operator/(const float& factor);
+  Polar operator/(const float &factor);
 
   /// <summary>
   /// The distance between two vectors
@@ -84,7 +88,7 @@ struct Polar {
   /// <param name="v1">The first vector</param>
   /// <param name="v2">The second vector</param>
   /// <returns>The distance between the two vectors</returns>
-  static float Distance(const Polar& v1, const Polar& v2);
+  static float Distance(const Polar &v1, const Polar &v2);
 
   /// <summary>
   /// Rotate the vector
@@ -95,4 +99,6 @@ struct Polar {
   static Polar Rotate(Polar v, float angle);
 };
 
+#include "Vector2.h"
+
 #endif
\ No newline at end of file
diff --git a/Vector2.cpp b/Vector2.cpp
index c2a74c0..dbf6562 100644
--- a/Vector2.cpp
+++ b/Vector2.cpp
@@ -116,7 +116,7 @@ float Vector2::SignedAngle(Vector2 from, Vector2 to) {
 
   float angleFrom = atan2(from.y, from.x);
   float angleTo = atan2(to.y, to.x);
-  return (angleTo - angleFrom) * Angle::Rad2Deg;
+  return -(angleTo - angleFrom) * Angle::Rad2Deg;
 }
 
 Vector2 Vector2::Rotate(Vector2 v, float angle) {
diff --git a/test/Polar_test.cc b/test/Polar_test.cc
new file mode 100644
index 0000000..ebadeee
--- /dev/null
+++ b/test/Polar_test.cc
@@ -0,0 +1,29 @@
+#if GTEST
+#include <gtest/gtest.h>
+#include <limits>
+#include <math.h>
+
+#include "Polar.h"
+
+#define FLOAT_INFINITY std::numeric_limits<float>::infinity()
+
+TEST(Polar, FromVector2) {
+  Vector2 v = Vector2(0, 1);
+  Polar p = Polar::Polar(v);
+
+  EXPECT_FLOAT_EQ(p.distance, 1.0F) << "p.distance 0 1";
+  EXPECT_FLOAT_EQ(p.angle, 0.0F) << "s.angle 0 0 1";
+
+  v = Vector2(1, 0);
+  p = Polar::Polar(v);
+
+  EXPECT_FLOAT_EQ(p.distance, 1.0F) << "p.distance 1 0";
+  EXPECT_FLOAT_EQ(p.angle, 90.0F) << "s.angle 1 0";
+
+  v = Vector2(-1, 1);
+  p = Polar::Polar(v);
+
+  EXPECT_FLOAT_EQ(p.distance, sqrt(2.0F)) << "p.distance -1 1";
+  EXPECT_NEAR(p.angle, -45.0F, 1.0e-05) << "s.angle -1 1";
+}
+#endif
\ No newline at end of file
diff --git a/test/Vector2_test.cc b/test/Vector2_test.cc
index 9303bb0..88b8c97 100644
--- a/test/Vector2_test.cc
+++ b/test/Vector2_test.cc
@@ -399,11 +399,11 @@ TEST(Vector2, SignedAngle) {
   bool r = false;
 
   f = Vector2::SignedAngle(v1, v2);
-  EXPECT_FLOAT_EQ(f, 12.09476F) << "SignedAngle(4 5, 1 2)";
+  EXPECT_FLOAT_EQ(f, -12.09476F) << "SignedAngle(4 5, 1 2)";
 
   v2 = Vector2(-1, -2);
   f = Vector2::SignedAngle(v1, v2);
-  EXPECT_FLOAT_EQ(f, -167.9052F) << "SignedAngle(4 5, -1 -2)";
+  EXPECT_FLOAT_EQ(f, 167.9052F) << "SignedAngle(4 5, -1 -2)";
 
   v2 = Vector2(0, 0);
   f = Vector2::SignedAngle(v1, v2);
@@ -420,6 +420,16 @@ TEST(Vector2, SignedAngle) {
     r = isnan(f);
     EXPECT_TRUE(r) << "SignedAngle(4 5, -INFINITY -INFINITY)";
   }
+
+  v1 = Vector2(0, 1);
+  v2 = Vector2(1, 0);
+  f = Vector2::SignedAngle(v1, v2);
+  EXPECT_FLOAT_EQ(f, 90.0F) << "SignedAngle(0 1, 1 0)";
+
+  v1 = Vector2(0, 1);
+  v2 = Vector2(0, -1);
+  f = Vector2::SignedAngle(v1, v2);
+  EXPECT_FLOAT_EQ(f, 180.0F) << "SignedAngle(0 1, 1 0)";
 }
 
 TEST(Vector2, Rotate) {