This page uses JavaSketchpad, a World-Wide-Web component of The Geometer's Sketchpad. Copyright © 1990-2011 by KCP Technologies, Inc. Licensed only for non-commercial use.

Please install Java (version 1.4 or later) to use JavaSketchpad applets.

Observe the proportions. Think about the following questions before you begin.

1. How do you think the proportions will behave when you adjust the length of segments AC and AD?

2. How do you think the proportions will behave when you move the segment BE?

Use the sliders in the top right corner to adjust the lengths of AC and AD. What do you notice?

Grab point B to move segment BE. What do you notice?

What conclusions can you make about the side lengths of the triangle and the propotions below?

Do you think this is true for all triangles?