MathDB
SMO 2014

Source:

May 22, 2015
geometry

Problem Statement

On sides BCBC and ACAC of ABC\triangle ABC given are DD and EE, respectively. Let FF (FCF \neq C) be a point of intersection of circumcircle of CED\triangle CED and line that is parallel to ABAB and passing through C. Let GG be a point of intersection of line FDFD and side ABAB, and let HH be on line ABAB such that HDA=GEB\angle HDA = \angle GEB and HABH-A-B. If DG=EHDG=EH, prove that point of intersection of ADAD and BEBE lie on angle bisector of ACB\angle ACB.
Proposed by Milos Milosavljevic