This is a proof of the Pythagorean Theorem as developed by and attributed to Albert Einstein. Of all the proofs that I have encountered, this proof is the most direct and intuitive that I know of. I hope that it will help you get a better feeling as to why the Pythagorean Theorem is true how the is the direct logical consequence of a triangle which has a right angle. Correction at 9:00 : U = ab/c^2 (denominator should have c squared)