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bisector of <BEA _|_ MR

Source: Mathematics Regional Olympiad of Mexico West 2021 P5

September 9, 2022
perpendiculargeometry

Problem Statement

Let ABCABC be a triangle such that ACAC is its shortest side. A point PP is inside it and satisfies that BP=ACBP = AC. Let RR be the midpoint of BCBC and let MM be the midpoint of APAP. Let EE be the intersection of BPBP and ACAC. Prove that the bisector of angle BEA\angle BE A is perpendicular to segment MRMR.