MathDB
Sharygin CR 2019 P6

Source:

March 6, 2019
geometrycyclic quadrilateral

Problem Statement

Two quadrilaterals ABCDABCD and A1B1C1D1A_1B_1C_1D_1 are mutually symmetric with respect to the point PP. It is known that A1BCDA_1BCD, AB1CDAB_1CD and ABC1DABC_1D are cyclic quadrilaterals. Prove that the quadrilateral ABCD1ABCD_1 is also cyclic
Back to ProblemsView on AoPS