Hello! I'm not sure this is the right place to ask, but i have a huge problem. I have an axis and it's origin, and also a point. I suposed that is enought to describe an ellipse, but how to do so? I want to describe it by having it's center and both it's radius. Some images to ilustrate what I am trying to say: http://img855.imageshack.us/img855/4003/img1b.png [Broken] Here you can see what I have: the red point and the black rect, and also the orange point (I don't know where in the black rect the ellipse is going to end, so I don't know it's diameter). I think it's pretty simple the way I want to describe it, but it's very uncommom, so: http://img266.imageshack.us/img266/3527/img2k.png [Broken] I want the red center point (x, y) and the numeric values of each radius (the blue and the yellow ones). I'd be really apreciated if anyone could help me with this problem. I've been looking for it for a long time now, but I just coudn't find an answer.