Albrecht Hess, Bicentric quadrilaterals through inversion,
Forum Geometricorum, 13 (2013) 11--15.

Abstract. We show that inversion is a delightful tool for making some recent and some older results on bicentric quadrilaterals more transparent and to smoothen their proofs. As a main result we give an illustrative interpretation of Yun's inequality and derive a sharper form.

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