Proof of Pythagorean Theorem

a2 + b2 = c2

Combination Geometric/Analytic Proof

The right figure is a visual display of the Pythagorean Theorem. The left figure contains a proof of the theorem. This is because the area of the big, outer, green square is equal to the sum of the areas of the four red triangles and the little, inner white square. The length of the blue lines is a. The length of the yellow lines is b. And, the length of the green lines is c. c2 = 4(ab/2) + (a-b)2 = 2ab + (a2 - 2ab + b2) = a2 + b2