Angles identified by a rotation of the plane
Source: Tournament of towns, Senior A-Level paper, Fall 2004
December 25, 2004
geometrygeometric transformationrotationgeometry solved
Problem Statement
Let AOB and COD be angles which can be identified by a rotation of the plane (such that rays OA and OC are identified). A circle is inscribed in each of these angles; these circles intersect at points E and F. Show that angles AOE and DOF are equal.