Education Technology


Investigating the Slopes of Parallel and Perpendicular lines

Activity Overview

In this activity, students investigate how equations of parallel and perpendicular lines relate to each other. They use the drawing and measurement tools of Cabri™ Jr. to explore the slopes of lines. NCTM Geometry Standards: Analyze characteristics and properties of 2- and 3-dimensional geometric shapes and develop mathematical arguments about geometric relationships. Specify locations and describe spatial relationships using coordinate geometry and other representational systems.

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 44 - 45 from the attached PDF file for your class
  • During the Activity

    Distribute the pages to your class.

    Follow the Activity procedures:

  • Draw a line
  • Draw a line parallel to the original line
  • Draw a line perpendicular to the original line
  • Explore the relationships between the slopes of parallel and perpendicular lines
  • After the Activity

    Review student results:

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