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 6 from the EXPLORATIONS Book:
Exploring Mathematics with Cabri™ Jr. Application
• ##### Report an Issue

Circles in the Plane

#### Activity Overview

In this activity, students will use the Cabri™ Jr. application to explore circles in a plane. They will investigate the relationship between the equation of a circle, the length of its radius, and the coordinates of its center.

#### 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 cables
• See the attached PDF file for detailed instructions for this activity
• Print pages 65 - 71 from the attached PDF file for your class
• #### During the Activity

Distribute the pages to your class.

Follow the Activity procedures:

• Show the coordinate axes and create a circle
• Measure the radius of the circle, display the equation of the circle, and the coordinates of the center
• Drag the circle, the center, and the radius point and observe the changes
• Construct a point on the circle, and measure its distance to the center
• Construct a point not on the circle, and measure its distance to the center
• Examine the relationship between the coordinates of the center, the length of the radius, and the equation of the circle
• #### After the Activity

Students will fill in the Data Collection and Analysis sheet.

Review student results:

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