Education Technology

Perimeters, Areas, and Slopes - Oh, My!

Published on 06/09/2008

Activity Overview

Students create geometric figures, and use analytic and coordinate geometry to investigate their attributes. They go through the process of proving that a quadrilateral is a parallelogram.

Before the Activity

Install the Inequality Graphing Application on the calculator 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 37-41 from the attached PDF file for your class

During the Activity

Distribute the pages to your class.

Follow the Activity procedures:

  • Position the quadrilateral in the Cartesian coordinate plane
  • Graph the system of inequalities that determines the quadrilateral and its feasible region
  • Shade the feasible region of the system of inequalities
  • Trace the graph and determine the coordinates of the other three vertices
  • Devise a strategy for determining whether the quadrilateral is a parallelogram (slopes of opposite sides are equal)
  • Provide mathematical evidence to support the conclusion
  • Determine the perimeter and area of the parallelogram
  • After the Activity

    Students will complete the Student Worksheet and answer questions listed in it.

    Review student results:

  • As a class, discuss questions that appeared to be more challenging
  • Re-teach concepts as necessary