Parallelism
Source: 2013 Baltic Way, Problem 14
December 31, 2013
geometrygeometric transformationhomothetyparallelogramangle bisectorgeometry unsolved
Problem Statement
Circles and of the same radius intersect in two points, one of which is . Denote by and , respectively, the points diametrically opposite to on each of and . A third circle of the same radius passes through and intersects and in the points and , respectively. Show that the line is parallel to the line .