Let Ca, Ba be points on AB, AC such that BCa = CBa = BC. Define analogously Ab, Cb, Bc, Cb. The lines CaBa, AbCb, BcAc bound a triangle A'B'C'; the lines BcCb, AcCa, BaAb bound a triangle A"B"C". The three triangles ABC, A'B'C', A"B"C" are perspective with center X(65).