(use with UCSMP Geometry, Lesson 1-7)
This applet helps demonstrate the triangle inequality. At the bottom of the screen you will see a rectangle cut into equal size pieces. Think of each of these pieces as a unit. You must group the pieces into three groups representing the three sides of a triangle. To do this click on two of the lines dividing the length at the bottom. After clicking the second line a short animation will begin. If the three lengths are able to form a triangle then the triangle will be formed. If not, the animation will show you that no triangle could be formed.
At the bottom of the screen there are several buttons. On the left side the button labeled "Clear Selection" will cancel any length selection you have already made. Using the text entry field and the "Reset!" button you can change the total number of pieces into which the segment will be divided, also this will clear away any triangles you have already found. The "Show All" button, will show every possible triangle that can be made from the given number of units.
You will notice that some triangles are different colors than others. This is to help distinguish the various types of triangles. Isoceles triangles are blue, equilateral triangles are red, right triangles are green and scalene triangles are black.