I would like to calculate (X,Y) coords on a circle with a 10" radius. I have some idea on how this can work but I'm not real solid on it. Say the center is (0,10) and I'd like to solve for Y given an arbitrary X. How would I do this? Obviously (10,0) and (-10,0) and (0,-10) and I know that sin and cos are going to come into it but not sure the actual formula here. Any help would be greatly appreciated. EDIT: Thinking a little bit sin()=opp/hyp and cos()=adj/hyp. opposite would be my Y travel and adjacent would be my X. And the radius=10. Theta would be 2*pi/?.