Proof of Pythagoras' Theorem

An applet that demonstrates a proof of the Pythagorean theorem was kindly sent to me by David King. The proof is similar to #12 in that it relies on a shearing transformation, yet I think it's sufficiently different to warrant its own place in the list of proofs. The text below is David's.

This simulation shows a simple graphical proof. It occurred to me while I was trying to get to sleep, and for a mad moment I thought it might be original. That was of course too much to hope for; it is just a variation on a well known theme. It's still quite therapeutic to watch though...

Click on the simulation to start or stop it.

This applet requires Sun's Java VM 2 which your browser may perceive as a popup. Which it is not. If you want to see the applet work, visit Sun's website at, download and install Java VM and enjoy the applet.

How it proves Pythagoras:

The red square on the hypoteneuse is just covered by the green and blue squares built on the other two sides, once they have been rotated and sheared into position.

[an error occurred while processing this directive]

|Pythagorean Theorem| |Contact| |Front page| |Contents| |Geometry|

Copyright © 1996-2018 Alexander Bogomolny
[an error occurred while processing this directive]
[an error occurred while processing this directive]