Sorry if i post this in the wrong spot. I am trying to form the curve of the half quadrant of a circle. And i wonder that how do we know which or where is our control point? For cubic bezier, the 2nd control point should be on the tangent line of the starting point and the 3rd control point should be on the tangent of the end point. But how do i know how far should i take? And how to combine them together? Do the controls points position change?