Rotating rectangular coordinates

The new set of coordinates (x0, y0) is assumed for any point (x, y) on the image, about a coordinate point (rx0, ry0) angle after a counterclockwise rotation, having the formula:
X0 = (X - RX0) * COS (A) - (Y - RY0) * SiN (A) + RX0;
yO = (X - RX0) * SiN (A) + (Y - RY0) * COS (A) + RY0;