Education Technology

Segments Formed by Intersecting Chords, Secants, and Tangents

Published on 06/09/2008

Activity Overview

This activity is designed to help students discover several important theorems concerning lengths of segments formed by intersecting chords, secants, and tangents.

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 189 - 192 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
  • Construct a circle with two intersecting chords
  • Use the Calculate tool to investigate the relationship between the four segments determined by intersecting chords
  • Construct a circle with two secants that intersect outside the circle
  • Construct a circle with a tangent and a secant that intersect outside the circle
  • Use the Calculate tool to investigate the relationship between the secant segments and their external segments
  • After the Activity

    Review student results:

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