MathDB
NO WAY - line intersects quad

Source: Sharygin Final 2024 8.7

August 2, 2024
geometrySharygin Geometry OlympiadSharygin 2024

Problem Statement

A convex quadrilateral ABCDABCD is given. A line l∥ACl \parallel AC meets the lines ADAD, BCBC, ABAB, CDCD at points XX, YY, ZZ, TT respectively. The circumcircles of triangles XYBXYB and ZTBZTB meet for the second time at point RR. Prove that RR lies on BDBD.
Back to ProblemsView on AoPS