Education Technology

Intersecting Lines and Vertical Angles

Activity Overview

In this activity, students visualize and explore the angles that are formed when two lines intersect. By measuring angles formed by intersecting lines, they enhance their understanding of vertical angles, supplementary angles, and a linear pair. NCTM Geometry Standard covered: Analyze characteristics and properties of 2- and 3-dimensional geometric shapes and develop mathematical arguments about geometric relationships.

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
  • See the attached PDF file for detailed instructions for this activity
  • Print pages 9-10 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
  • Measure one pair of vertical angles, using the Angle measure tool
  • Move a line to change the angles
  • Observe the changes in the angle measures
  • After the Activity

    Review student results:

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