Pythagorean Theorem - Proof Without Words

Right Triangle

We begin with a simple right triangle. We are given the following information:

• Two sides of a triangle meet at a right angle.
• The lengths of these two sides are a and b.
• The length of the third side, called the hypotenuse, is c.

Using these three facts, we want to show the three numbers a, b, and c obey the formula:

That is, the square of the length of the hypotenuse is equal to the sum of the squares of the lengths of the other two sides.