} // End function DotP
public static T Angle_Rad(MyVector2D <T> a, MyVector2D <T> b)
{
T axbx = Arithmetics <T> .Multiply(a.X, b.X);
T ayby = Arithmetics <T> .Multiply(a.Y, b.Y);
T azbz = Arithmetics <T> .ZERO;
T sumAB = Arithmetics <T> .Sum(axbx, ayby, azbz);
T ax2 = Arithmetics <T> .Pow(a.X, 2);
T ay2 = Arithmetics <T> .Pow(a.Y, 2);
T az2 = Arithmetics <T> .ZERO;
T bx2 = Arithmetics <T> .Pow(b.X, 2);
T by2 = Arithmetics <T> .Pow(b.Y, 2);
T bz2 = Arithmetics <T> .ZERO;
T aSquare = Arithmetics <T> .Sum(ax2, ay2, az2);
T bSquare = Arithmetics <T> .Sum(bx2, by2, bz2);
T val = Arithmetics <T> .Divide(sumAB,
(
Arithmetics <T> .Multiply(Arithmetics <T> .Sqrt(aSquare), Arithmetics <T> .Sqrt(bSquare))
)
);
T nReturnValue = Arithmetics <T> .Acos(val);
return(nReturnValue);
} // End function Angle_Rad