Determine the locus of points
Source: Sharygin contest 2008. The correspondence round. Problem 6
September 3, 2008
geometry proposedgeometry
Problem Statement
(A. Myakishev, 8--9) In the plane, given two concentric circles with the center . Let be an arbitrary point on some of these circles, and on the other one. For every triangle , consider two equal circles mutually tangent at the point , such that one of these circles is tangent to the line at point and the other one is tangent to the line at point . Determine the locus of points .