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Angle bisectors and parallel

Source: CSMO 2019 Grade 11 Problem 6

July 31, 2019
geometry

Problem Statement

In ABC\triangle ABC, AB>ACAB>AC, the bisectors of ABC,ACB\angle ABC, \angle ACB meet sides AC,ABAC,AB at D,ED,E respectively. The tangent at AA to the circumcircle of ABC\triangle ABC intersects EDED extended at PP. Suppose that AP=BCAP=BC. Prove that BDCPBD\parallel CP.