Education Technology

Tangents from the same exterior point with CABRI JR.

Activity Overview

Use Cabri™ Jr. to discover what happens when we have two tangents from the same exterior point. After students investigate with Cabri Jr. they have a questions and a flow-proof to complete.

Before the Activity

Students need either a TI-83 plus or TI-84 with CabriJr. loaded. This is a free application that comes standard with the TI-84, but can also be loaded on the TI-83 plus if the operating system has been updated.

During the Activity

In this activity students will:

  • Draw a circle
  • Draw two tangent lines
  • Find the point of intersection
  • Measure the distances
  • Animate one of the tangents
  • After the Activity

    Review student answers:

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