Pythagorean Theorem Activity

Below is a common proof of the Pythagorean Theorem. The yellow triangle has a right angle at B, and the black shapes are squares built on the sides of the triangle. Slide points A, B, and C around to change the shape of the yellow triangle. Watch what happens to the shapes and the areas of the sqaures.

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Questions to think about:
What happened to the areas of the squares?
How can this drawing help us prove the Pythagorean Theorem?

July 3, 2008, Created with GeoGebra