MathDB
Config geo with symmedian

Source: Serbia Additional IMO TST 2024, P3 (out of 4)

May 30, 2024
geometry

Problem Statement

Let ABCABC be a triangle with circumcenter OO, angle bisector ADAD with DBCD \in BC and altitude AEAE with EBCE \in BC. The lines AOAO and BCBC meet at II. The circumcircle of ADE\triangle ADE meets AB,ACAB, AC at F,GF, G and FGFG meets BCBC at HH. The circumcircles of triangles AHIAHI and ABCABC meet at JJ. Show that AJAJ is a symmedian in ABC\triangle ABC