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angle chasing in isosceles trapezoid (2012 From Tasks to Tasks, p4 Ukr)

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May 2, 2021
geometrytrapezoidangles

Problem Statement

Let ABCDABCD be an isosceles trapezoid (ADBCAD\parallel BC), BAD=80o\angle BAD = 80^o, BDA=60o\angle BDA = 60^o. Point PP lies on CDCD and PAD=50o\angle PAD = 50^o. Find PBC\angle PBC