Pythagoras Theorem Proof Pythagoras Theorem Proof in 1 Minute The Pythagoras Theorem states that in a right-angle triangle, the square of the hypotenuse equals the sum of the squares of the other two sides. Proof (Simple): Make a big square using four identical right-angle triangles. The area of the big square can be written in two ways: 1. As (a b)² 2. As area of 4 triangles small inner square = 4 × (½ab) c² Equate both: (a b)² = 2ab c² → a² b² = c². Hence proved. pythagoras theorem proof, righ