The Zipper of Pythagoras (Pythagorean Theorem)

In mathematics, the Pythagorean theorem, also known as Pythagoras' theorem, is a relation in Euclidean geometry among the three sides of a right triangle.

It states that the square of the hypotenuse (the side opposite the right angle) is equal to the sum of the squares of the other two sides.

Interestingly, (to me) the circle of the hypotenuse (the side opposite the right angle) is equal to the sum of the circles of the other two sides.

So a² + b² = c² works for an infinite number of shapes.

Yet teachers and students might enjoy this new construction, depicting what I call, the Pythagorean Zipper. 

Can you work out how we get from 1 to 7? Have fun!

The Zipper of Pythagoras  (Click to enlarge)