The figure below shows a triangle
ABC with the squares ABC_{1}C_{2}, BCA_{1}A_{2}, and ACB_{1}B_{2}. Prove that the
areas of triangles BB_{1}C_{1} and BB_{2}A_{2} are equal (equivalent
triangles).
See
also:
Art and typography of problem 1160
Kaleidoscope of Problem
1160 base on Poincare Disk Model.
