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concyclic and equal circles wanted, 3 squares related

Source: 2020 XXIII All-Ukrainian Tournament of Young Mathematicians named after M. Y. Yadrenko, Qualifying p12

May 4, 2021
geometrySquaresConcyclicequal circlesUkrainian TYM

Problem Statement

On the side CDCD of the square ABCDABCD, the point FF is chosen and the equal squares DGFEDGFE and AKEHAKEH are constructed (EE and HH lie inside the square). Let MM be the midpoint of DFDF, JJ is the incenter of the triangle CFHCFH. Prove that: a) the points D,K,H,J,FD, K, H, J, F lie on the same circle; b) the circles inscribed in triangles CFHCFH and GMFGMF have the same radii.