But ... the two points of intersection are always going to be the same = distance from the line joining the two points we were given. Now if we had 3 points there could be no doubt - except in the case you = mentioned where all given points are in the same place >>> mdippers@HARRIS.COM 01/10/02 04:11PM >>> 3. The two points are unique and less than twice the radius apart, so the circles intersect at two points. Case 3 is the interesting one. I haven't come up with a formal proof, but = I believe that the center of the original circle is the point of intersection= closest to the line through your two initial points. -Mike -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body