First off I'm not entirely sure this is a trig question. If it's in the wrong place could a moderator maybe move it? Using trig was just my inital thought on how to solve this problem but I could be extremely wrong.

So I'm a programmer and I'm working in 3D space. This is the problem I need to solve.

I have the points of A and B. I also have access to all the distances of all three sides of the triangle. All I need to do is find C. Basically I want the point perpindular to AB, that is a fixed distance away, directly above (or below) C. I feel like I'm missing something really simple but I just can't figure out what.

This would be a fairly simple problem to solve with some graph paper and a ruler but because this is for a computer program I need it to be in the form of some sort of equation that it will understand. It also needs to work for different values of A and B.

Thanks for any help. As I said please move this topic if I'm in the completely wrong area.