How Do You Calculate (X,Y) Coordinates on a Circle with a Given Radius?

[777funk]

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/?.

 

[dydxforsn]

It's x^2 + y^2 = 10^2. You can do (x - a)^2 + (y - b)^2 = r^2 for an arbitrary center point (if the circle is not centered at the origin). In such a case the point (a, b) is your center and 'r' is your radius value.

 

[777funk]

Ok, thanks. So I WAY over complicated things. Thanks for the help there.

As far as quick easy solving for various points, do you (or anyone else for that matter) have any software recommendations?