Education Technology

Angles Formed by Two Intersecting Lines

Activity Overview

Students will investigate the properties of angles formed by intersecting lines. They examine the definition of adjacent angles, supplementary angles, and vertical angles and learn about two important geometric theorems dealing with vertical and supplementary angles.

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
  • TI-Navigator™ "send to class" feature
  • See the attached PDF file for detailed instructions for this activity
  • Print pages 9 -11 from the attached PDF file for your class
  • During the Activity

    Distribute the pages to your class.

    Follow the Activity procedures:

  • Draw two intersecting lines and measure the angles formed
  • Identify all pairs of adjacent angles and vertical angles
  • Draw two adjacent angles that are supplementary
  • Measure the supplementary angles and calculate the sum
  • After the Activity

    Review student results

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