# Pythagorean theorem (check with ATP)

- Author:
- Zoltán Kovács

This applet demonstrates how GeoGebra can verify the Pythagorean theorem by using automated theorem proving in the background.

Use the Navigation Bar to create the construction:

- Create the first leg, side
*a*. - Draw a perpendicular in
*C*to side*a*, ensuring that the triangle will be right. - Create the second leg, side
*b*. - Create the hypothenuse, side
*c*. - Verify the theorem numerically.
- Check the theorem using automated theorem proving. In this case, the proof is a very long algebraic derivation by using analytical geometry and a huge equation system, but they are not shown.