IMO 1984 LL BEL4
Given a triangle ABC, three equilateral triangles AEB, BFC,
IMO 1984 LL BEL4
Origin: BEL
Problem
Given a triangle ABC, three equilateral triangles AEB, BFC, and CGA are constructed in the exterior of ABC. Prove that: (a) CE = AF = BG; (b) CE, AF, and BG have a common point.