I have a two points on the circle surface and I also know the center of the circle. I want to calculate the angle between those two points which are on the circle surface.
Is this formula is suitable to this situation?
$$\tan(\theta) = (y_2-y_1)/(x_2-x_1)$$
where $(x_1,y_1)$ are the one of the surface point $(x_2,y_2)$ is the other point on the surface.