Triangle Inequality

This application allows you to see why the sum of two sides must be greater than the third in order for a triangle to exist.
Adjust the side lengths accordingly, then move the blue points to try and create a triangle.

This is a Java Applet created using GeoGebra from - it looks like you don't have Java installed, please go to

My original file regarding the triangle inequality can be found here.

For more information regarding the triangle equality, look at this article From Guillermo Bautista at

David Travis
Lincoln North Star Math Department
Lincoln, NE

Created with GeoGebra