Shape 

Copyright David & Cynthia Thomas, 2009

 

Perimeter & Area of Polygons--Directed Activity: Inside a Parallelogram

                                                                     

Focus

Discovering properties of parallelograms

Technologies

The Geometers Sketchpad and model 3_ParallelogramProp.gsp.

Background

In Figure 3.20, diagonal AD and a segment drawn from B to E, the midpoint of side CD, divide the interior of parallelogram ABCD into polygonal regions. 

Figure 3.20: Polygons Inside a Parallelogram

 

Tasks

Using the Geometers Sketchpad model, investigate this figure thoroughly.  Look for relationships between the areas of the polygons formed in the interior of the parallelogram.  Look also for relationships between the segments formed.