Education Technology

# Activities

• ##### Subject Area

• Math: Geometry: Circles

9-12

90 Minutes

• ##### Device
• TI-83 Plus Family
• TI-84 Plus
• TI-84 Plus Silver Edition

TI Connect™

• ##### Accessories

TI Connectivity Cable

• ##### Other Materials
This is Activity 26 from the EXPLORATIONS Book:
Cabri™ Jr.: Interactive Geometry Activities and Investigations.

## Constructing Circles

#### Activity Overview

In this activity, students will investigate the construction of circles that pass through a given number of points. They will also investigate the number of points needed to generate a unique circle in a plane.

#### 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 173 - 174 from the attached PDF file for your class
• #### During the Activity

Distribute the pages to your class.

Follow the Activity procedures:

• Draw 3 points and construct a circle that passes through two points
• Draw circles passing through 3 points and a circle passing through 4 points
• Drag the given points and the defining points of the circle(s) to ensure that the circle(s) always passes through the given points
• #### After the Activity

Review student results:

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