MathDB
Geometry Mathley 15.2 concyclic

Source:

June 13, 2020
geometryConcyclic

Problem Statement

Let OO be the centre of the circumcircle of triangle ABCABC. Point DD is on the side BCBC. Let (K)(K) be the circumcircle of ABDABD. (K)(K) meets AOAO at EE that is distinct from AA. (a) Prove that B,K,O,EB,K,O,E are on the same circle that is called (L)(L). (b) (L)(L) intersects ABAB at FF distinct BB. Point GG is on (L)(L) such that EG∥OFEG \parallel OF. GKGK meets ADAD at S,SOS, SO meets BCBC at TT . Prove that O,E,T,CO,E, T,C are on the same circle.
Trần Quang Hùng
Back to ProblemsView on AoPS