MathDB
Equality of areas for equilateral triangles on sides...

Source: Vietnam MO 1982 P3

March 17, 2011
geometrygeometry unsolved

Problem Statement

Let be given a triangle ABCABC. Equilateral triangles BCA1BCA_1 and BCA2BCA_2 are drawn so that AA and A1A_1 are on one side of BCBC, whereas A2A_2 is on the other side. Points B1,B2,C1,C2B_1,B_2,C_1,C_2 are analogously defined. Prove that SABC+SA1B1C1=SA2B2C2.S_{ABC} + S_{A_1B_1C_1} = S_{A_2B_2C_2}.
Back to ProblemsView on AoPS