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T,H,E,B are concyclic

Source: Tuymaada 2024 Junior P4

July 10, 2024
geometry

Problem Statement

A triangle ABCABC is given. NN and MM are the midpoints of ABAB and BCBC, respectively. The bisector of angle BB meets the segment MNMN at EE. HH is the base of the altitude drawn from BB in the triangle ABCABC. The point TT on the circumcircle of ABCABC is such that the circumcircles of TMNTMN and ABCABC are tangent. Prove that points T,H,E,BT, H, E, B are concyclic. Proposed by M. Yumatov