MathDB
Crazy geometry on incircles

Source: Kyiv City MO 2022 Round 2, Problem 11.4

January 30, 2022
geometry

Problem Statement

Let ABCDABCD be the cyclic quadrilateral. Suppose that there exists some line ll parallel to BDBD which is tangent to the inscribed circles of triangles ABC,CDAABC, CDA. Show that ll passes through the incenter of BCDBCD or through the incenter of DABDAB.
(Proposed by Fedir Yudin)
Back to ProblemsView on AoPS