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<ACB=? <BAC=20,<CAD=60, <ADB=<50, <BDC =10 (2019 Auckland MO J1)

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December 31, 2020
geometryangles

Problem Statement

Given a convex quadrilateral ABCDABCD in which BAC=20o\angle BAC = 20^o, CAD=60o\angle CAD = 60^o, ADB=50o\angle ADB = 50^o , and BDC=10o\angle BDC = 10^o. Find ACB\angle ACB.