MathDB
2015 JBMO Shortlist G1

Source: 2015 JBMO Shortlist G1

October 8, 2017
geometryJBMO

Problem Statement

Around the triangle ABCABC the circle is circumscribed, and at the vertex C{C} tangent t{t} to this circle is drawn. The line p{p}, which is parallel to this tangent intersects the lines BC{BC} and AC{AC} at the points D{D} and E{E}, respectively. Prove that the points A,B,D,EA,B,D,E belong to the same circle.
(Montenegro)