Education Technology

Dilations in the Plane

Published on 06/09/2008

Activity Overview

In this activity, students will learn to use the Dilation tool on the Cabri™ Jr. application. They will also investigate the properties of dilations and the effects of dilations in the coordinate plane.

Before the Activity

  • Install the Cabri Jr. App on the students' graphing calculators using TI-Connect™, a TI Connectivity Cable and the Unit-to-Unit Link Cable
  • Use the TI-Navigator™ to transfer the attached Cabri Jr. AppVar files to each calculator
  • See the attached PDF file for detailed instructions for this activity
  • Print pages 63 - 66 from the attached PDF file for your class
  • During the Activity

    Distribute the pages to your class.

    Follow the Activity procedures:

  • Use the AppVar to go directly to the exploration section
  • Create a dilation factor tool
  • Draw a triangle to dilate, and a point that will be the center of the dilation
  • Dilate the triangle using the dilation factor tool
  • Observe the relationship between the pre-image and the image formed by the dilation using measurement tools (Distance and length, angle, and slope)
  • After the Activity

    Review student results:

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