Activity Overview
In this activity, students go through the process of proving a quadrilateral to be a parallelogram. They understand the various characteristics of a parallelogram.
Before the Activity
Install the Cabri™: Jr. App on the students' graphing calculators using one of these two methods:
TI-Connect™, a TI Connectivity Cable, and the Unit-to-Unit Link Cable
TI-Navigator™ "send to class" feature
See the attached PDF file for detailed instructions for this activity
Print pages 37 - 39 from the attached PDF file for your class
During the Activity
Distribute the pages to your class.
Follow the Activity procedures:
Construct a parallelogram
Find and label the lengths of all the sides
Observe that the opposite sides are congruent
Alter the parallelogram and check this relationship
Find and label the measure of all the angles
Alter the parallelogram and observe that the opposite angles stay congruent
Note that the consecutive angles are supplementary
Drag the vertex and verify if this relationship is maintained
Construct diagonals and determine the point of intersection
Measure the distance between the point of intersection of the diagonals and the vertices of the parallelogram
Observe that the diagonals bisect each other
Note that if a quadrilateral is a parallelogram, then its opposite sides are congruent, opposite angles are congruent, consecutive angles are supplementary, and diagonals bisect each other
After the Activity
Review student results:
As a class, discuss questions that appeared to be more challenging
Re-teach concepts as necessary