GeoGebra 4.0 release candidate and GeoGebra 4.2

The GeoGebra 4.0 Release Candidate is now online. Here is the announcement of the GeoGebra Team about it.

According to the team, the GeoGebra 4.0 offline installers will be released in a few weeks. You can also now explore the new GeoGebra 4.2 Beta.

July 2011 Top Posts

Here are the most popular posts for July 2011. Enjoy exploring. 

1. The Pantograph
2. Circle Approximation Graph
3. Viviani's Theorem created with GeoGebra 4.0 beta
4. Circles and Arbelos
5. Triangles and Quadrilaterals
6. Visualizing Multiplication of Fractions
7. The GeoGebra 4.0 Sneak Peek Series
8. Approximating the area of a circle
9. The Eutrigon Theorem
10. Circumcenter of a Triangle

Viviani's Theorem created with GeoGebra 4.0 beta

Viviani's theorem, named after Vincenzo Viviani, states that the sum of the distances from a point to the sides of an equilateral triangle equals the length of the triangle's altitude.


This is a Java Applet created using GeoGebra from www.geogebra.org - it looks like you don't have Java installed, please go to www.java.com


The theorem can be extended to equilateral polygons and equiangular polygons. Specifically, the sum of distances from a point to the side lines of an equiangular (or equilateral) polygon does not depend on the point.

Text Source: Wikipedia

Download GGB file