MathDB
ABCD, <ABC+<DBC=<ADC+<BDC=180^o (2013 From Tasks to Tasks, p13 Ukr)

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May 2, 2021
anglesCircumcentergeometry

Problem Statement

In the quadrilateral ABCDABCD it is known that ABC+DBC=180oABC + DBC = 180^o and ADC+BDC=180oADC + BDC = 180^o. Prove that the center of the circle circumscribed around the triangle BCDBCD lies on the diagonal ACAC.
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