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given cyclic ABCD with metric relations + angle, find radius (Chile 2015 L1 P5)

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May 26, 2019
geometrycyclic quadrilateralradius

Problem Statement

A quadrilateral ABCDABCD is inscribed in a circle. Suppose that DA=BC=2|DA| =|BC|= 2 andAB=4 |AB| = 4. Let EE be the intersection point of lines BCBC and DADA. Suppose that AEB=60o\angle AEB = 60^o and that CD<AB|CD| <|AB|. Calculate the radius of the circle.