WSP Proof Without Words Pythagorean Theorem

• ## Proof Without Words: Pythagorean Theorem

Why is c2 = a2 + b2? Watch a dynamic, geometric "proof without words" of the Pythagorean Theorem. Can you explain the proof?

### How to Use

Use the red points on the sliders to adjust the lengths of the sides of the triangle.

### Buttons

• The buttons are meant to be used sequentially, and will appear in the order in which they are meant to be pressed.
• Be sure to allow all movements to cease before pressing another button, as this will affect the performance of the sketchpad.
• The Reset button will allow you to start over.

### Exploration

• Why does this proof work? Construct a proof.
• Do some research online to find other ways to prove the Pythagorean Theorem.

### Objectives and Standards

NCTM Standards and Expectations
• Geometry / Measurement
• Understand that by similarity, side ratios in right triangles are properties of the angles in the triangle, leading to definitions of trigonometric ratios for acute angles.
• 6-8
• Geometry