MathDB
Geometry with hexagon

Source: Moscow Olympiad 2018, Grade 11, P5

April 7, 2018
geometry

Problem Statement

On the sides of the convex hexagon ABCDEFABCDEF into the outer side were built equilateral triangles ABC1ABC_1, BCD1BCD_1, CDE1CDE_1, DEF1DEF_1, EFA1EFA_1 and FAB1FAB_1. The triangle B1D1F1B_1D_1F_1 is equilateral too. Prove that, the triangle A1C1E1A_1C_1E_1 is also equilateral.
Back to ProblemsView on AoPS