Here is a rotating 3D Proof of the Pythagorean Theorem (
) that I built out of wood, plexiglass, and sand.
The Pythagorean Theorem states that if you know two sides of a right triangle, you can find the length of the third with the relationship of . This can be proved by saying the sum of the areas of two squares with sides of length a and length b is equal to the area of the third square with a side lengths of c. In this model, the sand that fills the first two squares, rotates to fill the third larger square. The triangle in the middle set the length of the sides of the squares, thus proving the relationship.
