public void DegreeToRadian()
{
Assert.Equal(0, Math2.DegreeToRadian(0));
Assert.Equal((float)Math.PI / 4f, Math2.DegreeToRadian(45));
Assert.Equal(-(float)Math.PI / 4f, Math2.DegreeToRadian(-45));
Assert.Equal((float)Math.PI / 2f, Math2.DegreeToRadian(90));
Assert.Equal((float)Math.PI, Math2.DegreeToRadian(180));
Assert.Equal((float)Math.PI * 1.5f, Math2.DegreeToRadian(270));
Assert.Equal((float)Math.PI * 2f, Math2.DegreeToRadian(360));
Assert.Equal(-(float)Math.PI * 2f, Math2.DegreeToRadian(-360));
}