Incorporate technology in your class and let GeoGebra be your key partner in the learning process.
In this interactive applet, one of the most popular proofs of the Pythagorean Theorem is presented.
A vertical slider in the control area guides you through the steps that need to be followed in order to prove the Pythagorean Theorem. In each step, a short text shows up which explains what is happening in the main window of the applet. The refresh button on the top right corner clears everything up and allows the user to repeat the process.
An outline of the proof:
Four identical right triangles with leg lengths a and b and hypotenuse length c are arranged to form a big square with side length a+b. The leftover part of this arrangement is a square with side length c^2. Then, a different arrangement of these four triangles is made and the leftover part is two squares with side length a^2 and b^2 respectively. This leads to c^2=a^2+b^2.
This description is also included in the product as a printable word document.
To be able to see and play with the applet you will need to download and install the free software GeoGebra in your computer or tablet if you haven’t done this before. The process is very simple and quick: The link is
from which you can download GeoGebra Classic 5 (this is the version that I also use).