Geogebra is an open source mathematics program that is so good that that previously bored students find may themselves intrigued by mathematics.

Everything about the program is slick. The drawings it generates look good, and it’s fairly intuitive to use.

Where it shines is in the ability to move one line or one point, and see the rest of the drawing move within the constraints provided. Move one point of a triangle and the lengths of two adjoining sides of the triangle change. Values for angles and the lengths of the sides change accordingly. But it’s not just for geometry – this program also lets you plot charts for equations as fast as you can type in the equation.

It gives students the opportunity to explore mathematics instead of struggle with it.

This is an extremely sophisicated program, so mastering all its features will take a little time, however the learning curve is fairly gentle and there’s ample help, tutorials, and examples available. The program runs in stand-alone mode on a computer (requires java to be already installed), or as a java applet in a browser. It’s already a fantastic program, but since it’s actively developing open-source freeware, it will probably be even better down the track.

The last two screen shots are two of the many activities using GeoGebra at Henrico Public Schools, which includes four interactive demonstrations of Pythagorus’ Theorem.

Sliced bread for mathematics at last!