“In right-angled triangles the square on the side subtending the right angle is equal to the squares on the sides containing the right angle.” — Euclid, Elements, Book I, Proposition 47

The Pythagorean theorem describes the relationship between the three sides of a right triangle. Although associated with the Greek mathematician Pythagoras, the relationship was known to earlier civilizations (see Stigler's Law). It is one of the most fundamental results in geometry. The theorem has been proved numerous times by many different methods – possibly the most for any mathematical theorem. (One proof was made by James A. Garfield, 20th president of the United States)

The rearrangement proof shown in the design is more complex the the one in Euclid's elements