Education Technology

Segments Formed by Intersecting Chords, Secants, and Tangents

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