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MathNet 2012 Question 50

Math Olympiad Vault · MathNet 2012

Question 50

Let $ABCDE$ be a convex pentagon, for which the quadrilateral $ABCD$ is a square. If $\angle AEC + \angle BED = 180^\circ$, show that the pentagon $ABCDE$ is circumscribed by a circle. Here, by a convex pentagon we mean a pentagon for which each of the inner angles is less than $180^\circ$.

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