How is CATransform3DMakeRotation used?

The first is the angle in radians the other 3 parameters are the axis (x, y, z). So for example if you want to rotate 180 degrees around the z axis just call the function like this:

myView.layer.transform = CATransform3DMakeRotation(M_PI, 0.0, 0.0, 1.0);

and apply the result to the transform property of the view you want to rotate.

They represent the axis about which you want to rotate. Use 0,0,1 to rotate in the plane of the screen.

You'll probably find these useful when using radians:

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

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