Degrees to radians conversion.

gistfile1.txt

CGFloat DegreesToRadians(CGFloat degrees)
{
    return degrees * M_PI / 180;
};

CGFloat RadiansToDegrees(CGFloat radians)
{
    return radians * 180 / M_PI;
};


CGFloat DistanceBetweenTwoPoints(CGPoint pointA, CGPoint pointB)
{
    CGFloat dx = pointB.x - pointA.x;
    CGFloat dy = pointB.y - pointA.y;
    
    return sqrt(dx*dx + dy*dy);
};


double AngleBetweenThreePoints(CGPoint pointA, CGPoint pointB, CGPoint pointC)
{
    CGFloat a = pointB.x - pointA.x;
    CGFloat b = pointB.y - pointA.y;
    CGFloat c = pointB.x - pointC.x;
    CGFloat d = pointB.y - pointC.y;
    
    CGFloat atanA = atan2(a, b);
    CGFloat atanB = atan2(c, d);
    
    return atanB - atanA;
}