# circles...

• Jul 25th 2006, 03:06 AM
kevd
circles...
I have a point a 3D space (say 0,0,0), a radius of the circle(say 2m), and know a single point that lies on the circle at a certain x co-ordinate, and have the corresponding y coordinate for the point on the circle. How can I calculate the Z co-ordinate for this point given the above parameters?
• Jul 25th 2006, 05:37 AM
CaptainBlack
Quote:

Originally Posted by kevd
I have a point a 3D space (say 0,0,0), a radius of the circle(say 2m), and know a single point that lies on the circle at a certain x co-ordinate, and have the corresponding y coordinate for the point on the circle. How can I calculate the Z co-ordinate for this point given the above parameters?

Either I have misunderstood your question, or there is no way, a circle in 3D
is not determined by centre, radius and a point. You need at least two points.

RonL
• Jul 25th 2006, 06:07 AM
kevd
its ok, i probably explained it badly, i figured it out 5 mins after posting, and forgot to withdraw the post. Cheers anyway