
It worked, didn't it? You just fitted the area of the squares along the legs into the square along the hypotenuse. This relationship has been known for a long time. Pythagoras is said to be the first to have proven that it works in all right triangles. Since then it is called the Pythagorean theorem. Pythagorean theorem: In a right triangle the square of the measure of the hypotenuse is equal to the the sum of the squares of the measures of the legs. or in the arithmetic form: If a and b are the legs of a right triangle and c is its hypotenuse, then a^{2}+b^{2}=c^{2}. Below is a simple proof for the Pythagorean theorem. 

