https://artofproblemsolving.com/community/c6t48f6h3405388_a_proof_from_geometry

 

2 aops problems

 

Nelson Tunala, Geometria (solo trazos)

 

Jafar Nikpour, Training Geometry Olympiad

 

Levent Divriklinoglu, Sorunun-zoru

 Below a synthetic solution, little bit obscure, lacking calculations/explanations

Sorunun-zoru, Levent Devriklinoglu

 

Peru Geometrico, Stanley Rabinowitz, Square and 2 equilateral triangles