pytagorean theorem

To prove Pythagoras was right
With new-found ease and much delight, --

Let's say hypotenuse is c,
With one leg a and 'tother b.

On c we draw a square with pride,
Then triangles on every side.

The square of (a + b), you see,
Is c squared plus two times ab.

Equate and cancel 2ab
--- And we have reached the Q.E.D.