diff --git a/src/angle.rs b/src/angle.rs
index c43a078..b487514 100644
--- a/src/angle.rs
+++ b/src/angle.rs
@@ -1,94 +1,52 @@
+use core::f64::consts::pi;
 use num::cast::*;
 use vec::Vec3;
 
-pub enum Angle<T> {
-    degrees(T),
-    radians(T),
+pub trait Angle<T>: Add<self,self>
+                  , Sub<self,self>
+                  , Mul<T,self>
+                  , Div<T,self>
+                  , Modulo<T,self>
+                  , Neg<self> {
+    pure fn to_radians() -> Radians<T>;
+    pure fn to_degrees() -> Degrees<T>;
 }
 
-pub impl<T:Copy Num NumCast> Angle<T> {
-    pure fn degrees() -> T {
-        match self {
-            degrees(theta) => theta,
-            radians(theta) => theta * cast(180f64 / f64::consts::pi)
-        }
-    }
+pub enum Radians<T> = T;
+
+pub impl<T:Copy Num NumCast> Radians<T>: Angle<T> {
+    #[inline(always)] pure fn to_radians() -> Radians<T> { self }
+    #[inline(always)] pure fn to_degrees() -> Degrees<T> { Degrees(*self * cast(180.0 / pi)) }
     
-    pure fn radians() -> T {
-        match self {
-            degrees(theta) => theta * cast(f64::consts::pi / 180f64),
-            radians(theta) => theta
-        }
-    }
+    #[inline(always)] pure fn add(rhs: &Radians<T>) -> Radians<T> { self + *rhs }
+    #[inline(always)] pure fn sub(rhs: &Radians<T>) -> Radians<T> { self - *rhs }
+    #[inline(always)] pure fn mul(rhs: &T)          -> Radians<T> { self * *rhs }
+    #[inline(always)] pure fn div(rhs: &T)          -> Radians<T> { self / *rhs }
+    #[inline(always)] pure fn modulo(rhs: &T)       -> Radians<T> { self % *rhs }
+    #[inline(always)] pure fn neg()                 -> Radians<T> {-self }
 }
 
-pub impl<T:Copy Num> Angle<T>: Add<T,Angle<T>> {
-    #[inline(always)]
-    pure fn add(rhs: &T) -> Angle<T> {
-        match self {
-            degrees(theta) => degrees(theta + *rhs),
-            radians(theta) => radians(theta + *rhs)
-        }
-    }
-}
+pub enum Degrees<T> = T;
 
-pub impl<T:Copy Num> Angle<T>: Sub<T,Angle<T>> {
-    #[inline(always)]
-    pure fn sub(rhs: &T) -> Angle<T> {
-        match self {
-            degrees(theta) => degrees(theta - *rhs),
-            radians(theta) => radians(theta - *rhs)
-        }
-    }
-}
-
-pub impl<T:Copy Num> Angle<T>: Mul<T,Angle<T>> {
-    #[inline(always)]
-    pure fn mul(rhs: &T) -> Angle<T> {
-        match self {
-            degrees(theta) => degrees(theta * *rhs),
-            radians(theta) => radians(theta * *rhs)
-        }
-    }
-}
-
-pub impl<T:Copy Num> Angle<T>: Div<T,Angle<T>> {
-    #[inline(always)]
-    pure fn div(rhs: &T) -> Angle<T> {
-        match self {
-            degrees(theta) => degrees(theta / *rhs),
-            radians(theta) => radians(theta / *rhs)
-        }
-    }
-}
-
-pub impl<T:Copy Num> Angle<T>: Modulo<T,Angle<T>> {
-    #[inline(always)]
-    pure fn modulo(rhs: &T) -> Angle<T> {
-        match self {
-            degrees(theta) => degrees(theta % *rhs),
-            radians(theta) => radians(theta % *rhs)
-        }
-    }
-}
-
-pub impl<T:Copy Num> Angle<T>: Neg<Angle<T>> {
-    #[inline(always)]
-    pure fn neg() -> Angle<T> {
-        match self {
-            degrees(theta) => degrees(-theta),
-            radians(theta) => radians(-theta)
-        }
-    }
+pub impl<T:Copy Num NumCast> Degrees<T>: Angle<T> {
+    #[inline(always)] pure fn to_radians() -> Radians<T> { Radians(*self * cast(pi / 180.0)) }
+    #[inline(always)] pure fn to_degrees() -> Degrees<T> { self }
+    
+    #[inline(always)] pure fn add(rhs: &Degrees<T>) -> Degrees<T> { self + *rhs }
+    #[inline(always)] pure fn sub(rhs: &Degrees<T>) -> Degrees<T> { self - *rhs }
+    #[inline(always)] pure fn mul(rhs: &T)          -> Degrees<T> { self * *rhs }
+    #[inline(always)] pure fn div(rhs: &T)          -> Degrees<T> { self / *rhs }
+    #[inline(always)] pure fn modulo(rhs: &T)       -> Degrees<T> { self % *rhs }
+    #[inline(always)] pure fn neg()                 -> Degrees<T> {-self }
 }
 
 pub struct AxisRotation<T> {
     axis: Vec3<T>,
-    theta: Angle<T>,
+    theta: Radians<T>,
 }
 
 pub struct Euler<T> {
-    x: T,   // pitch
-    y: T,   // yaw
-    z: T,   // roll
+    x: Radians<T>,   // pitch
+    y: Radians<T>,   // yaw
+    z: Radians<T>,   // roll
 }
\ No newline at end of file
diff --git a/src/funs/projection.rs b/src/funs/projection.rs
index 1240895..7ec9e7f 100644
--- a/src/funs/projection.rs
+++ b/src/funs/projection.rs
@@ -12,7 +12,7 @@ use num::ext::FloatExt;
 //  http://www.opengl.org/wiki/GluPerspective_code
 //
 #[inline(always)]
-pure fn perspective<T:Copy FloatExt>(fovy: Angle<T>, aspectRatio: T, near: T, far: T) -> Mat4<T> {
+pure fn perspective<T:Copy FloatExt>(fovy: Radians<T>, aspectRatio: T, near: T, far: T) -> Mat4<T> {
     let ymax = near * tan(&fovy);
     let xmax = ymax * aspectRatio;
     return frustum(-xmax, xmax, -ymax, ymax, near, far);
diff --git a/src/funs/test/test_transform.rs b/src/funs/test/test_transform.rs
index 9b0b9e1..907ec5c 100644
--- a/src/funs/test/test_transform.rs
+++ b/src/funs/test/test_transform.rs
@@ -1,5 +1,5 @@
 use funs::transform::*;
-use angle::degrees;
+use angle::Degrees;
 use mat::Mat4;
 use vec::{Vec3, Vec4};
 
@@ -8,7 +8,7 @@ fn test_mat4_from_rotation() {
     {
         let pos = Vec4::new(1f32, 0f32, 0f32, 1f32);
         // let tform = mat4_from_rotation(180f32, Vec3::unit_z());
-        let tform = mat4_from_rotation(degrees(180f32), Vec3::new(0f32, 0f32, 1f32));
+        let tform = mat4_from_rotation(Degrees(180f32).to_radians(), Vec3::new(0f32, 0f32, 1f32));
         let newpos = tform.mul_v(&pos);
         
         let expected = Vec4::new(-1f32, 0f32, 0f32, 1f32);
@@ -20,8 +20,8 @@ fn test_mat4_from_rotation() {
         
         // let tform_a = mat4_from_rotation(90f32,  Vec3::unit_y());
         // let tform_b = mat4_from_rotation(90f32, -Vec3::unit_y());
-        let tform_a = mat4_from_rotation(degrees(90f32),  Vec3::new(0f32, 1f32, 0f32));
-        let tform_b = mat4_from_rotation(degrees(90f32), -Vec3::new(0f32, 1f32, 0f32));
+        let tform_a = mat4_from_rotation(Degrees(90f32).to_radians(),  Vec3::new(0f32, 1f32, 0f32));
+        let tform_b = mat4_from_rotation(Degrees(90f32).to_radians(), -Vec3::new(0f32, 1f32, 0f32));
         let newpos_a = tform_a.mul_v(&pos);
         let newpos_b = tform_b.mul_v(&pos);
         
diff --git a/src/funs/transform.rs b/src/funs/transform.rs
index f818091..7eb35a8 100644
--- a/src/funs/transform.rs
+++ b/src/funs/transform.rs
@@ -3,7 +3,7 @@ use angle::Angle;
 use mat::{Mat3, Mat4};
 use num::cast::*;
 
-pub pure fn mat3_from_rotation<T:Copy Num NumCast>(theta: Angle<T>, axis: Vec3<T>) -> Mat3<T> {
+pub pure fn mat3_from_rotation<T:Copy Num NumCast>(theta: Radians<T>, axis: Vec3<T>) -> Mat3<T> {
     let c:  T = cos(&theta);
     let s:  T = sin(&theta);
     let _0: T = cast(0);
@@ -15,6 +15,6 @@ pub pure fn mat3_from_rotation<T:Copy Num NumCast>(theta: Angle<T>, axis: Vec3<T
               t * axis.x * axis.z - s - axis.y, t * axis.y * axis.z - s * axis.x, t * axis.z * axis.z + c)
 }
 
-pub pure fn mat4_from_rotation<T:Copy Num NumCast>(theta: Angle<T>, axis: Vec3<T>) -> Mat4<T> {
+pub pure fn mat4_from_rotation<T:Copy Num NumCast>(theta: Radians<T>, axis: Vec3<T>) -> Mat4<T> {
   mat3_from_rotation(theta, axis).to_mat4()
 }
\ No newline at end of file
diff --git a/src/funs/trig.rs b/src/funs/trig.rs
index 55d8e7a..0dd2acf 100644
--- a/src/funs/trig.rs
+++ b/src/funs/trig.rs
@@ -17,10 +17,10 @@ priv trait Trig<T> {
 #[inline(always)] pub pure fn cos<T:Trig<R>, R>(theta: &T) -> R { theta.cos() }
 #[inline(always)] pub pure fn tan<T:Trig<R>, R>(theta: &T) -> R { theta.tan() }
 
-priv impl<T:Copy Num NumCast> Angle<T>: Trig<T> {
-    #[inline(always)] pure fn sin() -> T { cast(f64::sin(cast(self.radians()))) }
-    #[inline(always)] pure fn cos() -> T { cast(f64::cos(cast(self.radians()))) }
-    #[inline(always)] pure fn tan() -> T { cast(f64::tan(cast(self.radians()))) }
+priv impl<T:Copy Num NumCast> Radians<T>: Trig<T> {
+    #[inline(always)] pure fn sin() -> T { cast(f64::sin(cast(*self))) }
+    #[inline(always)] pure fn cos() -> T { cast(f64::cos(cast(*self))) }
+    #[inline(always)] pure fn tan() -> T { cast(f64::tan(cast(*self))) }
 }
 
 ///
@@ -29,31 +29,31 @@ priv impl<T:Copy Num NumCast> Angle<T>: Trig<T> {
 /// http://en.wikipedia.org/wiki/Inverse_trigonometric_functions
 ///
 pub trait InvTrig {
-    pure fn asin() -> Angle<self>;
-    pure fn acos() -> Angle<self>;
-    pure fn atan() -> Angle<self>;
+    pure fn asin() -> Radians<self>;
+    pure fn acos() -> Radians<self>;
+    pure fn atan() -> Radians<self>;
 }
 
-#[inline(always)] pub pure fn asin<T:InvTrig>(x: &T) -> Angle<T> { x.asin() }
-#[inline(always)] pub pure fn acos<T:InvTrig>(x: &T) -> Angle<T> { x.acos() }
-#[inline(always)] pub pure fn atan<T:InvTrig>(x: &T) -> Angle<T> { x.atan() }
+#[inline(always)] pub pure fn asin<T:InvTrig>(x: &T) -> Radians<T> { x.asin() }
+#[inline(always)] pub pure fn acos<T:InvTrig>(x: &T) -> Radians<T> { x.acos() }
+#[inline(always)] pub pure fn atan<T:InvTrig>(x: &T) -> Radians<T> { x.atan() }
 
 pub impl f32: InvTrig {
-    #[inline(always)] pure fn asin() -> Angle<f32> { radians(f32::asin(self)) }
-    #[inline(always)] pure fn acos() -> Angle<f32> { radians(f32::acos(self)) }
-    #[inline(always)] pure fn atan() -> Angle<f32> { radians(f32::atan(self)) }
+    #[inline(always)] pure fn asin() -> Radians<f32> { Radians(f32::asin(self)) }
+    #[inline(always)] pure fn acos() -> Radians<f32> { Radians(f32::acos(self)) }
+    #[inline(always)] pure fn atan() -> Radians<f32> { Radians(f32::atan(self)) }
 }
 
 pub impl f64: InvTrig {
-    #[inline(always)] pure fn asin() -> Angle<f64> { radians(f64::asin(self)) }
-    #[inline(always)] pure fn acos() -> Angle<f64> { radians(f64::acos(self)) }
-    #[inline(always)] pure fn atan() -> Angle<f64> { radians(f64::atan(self)) }
+    #[inline(always)] pure fn asin() -> Radians<f64> { Radians(f64::asin(self)) }
+    #[inline(always)] pure fn acos() -> Radians<f64> { Radians(f64::acos(self)) }
+    #[inline(always)] pure fn atan() -> Radians<f64> { Radians(f64::atan(self)) }
 }
 
 pub impl float: InvTrig {
-    #[inline(always)] pure fn asin() -> Angle<float> { radians(f64::asin(cast(self)).to_float()) }
-    #[inline(always)] pure fn acos() -> Angle<float> { radians(f64::acos(cast(self)).to_float()) }
-    #[inline(always)] pure fn atan() -> Angle<float> { radians(f64::atan(cast(self)).to_float()) }
+    #[inline(always)] pure fn asin() -> Radians<float> { Radians(f64::asin(cast(self)).to_float()) }
+    #[inline(always)] pure fn acos() -> Radians<float> { Radians(f64::acos(cast(self)).to_float()) }
+    #[inline(always)] pure fn atan() -> Radians<float> { Radians(f64::atan(cast(self)).to_float()) }
 }
 
 ///
diff --git a/src/quat.rs b/src/quat.rs
index 840342b..8b66969 100644
--- a/src/quat.rs
+++ b/src/quat.rs
@@ -222,7 +222,7 @@ pub impl<T:Copy Num NumCast Exp Clamp Ord InvTrig> Quat<T>: Quaternion<T> {
     }
 
     #[inline(always)]
-    pub pure fn from_axis_angle(axis: Vec3<T>, theta: Angle<T>) -> Quat<T> {
+    pub pure fn from_axis_angle(axis: Vec3<T>, theta: Radians<T>) -> Quat<T> {
         let half = theta / cast(2);
         Quat::from_sv(cos(&half), axis.mul_t(sin(&half)))
     }