Education Technology

# Activities

• ##### Subject Area

• Math: Geometry: Transformational Geometry

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 8 from the EXPLORATIONS Book:
Cabri™ Jr.: Interactive Geometry Activities and Investigations.

## Rotations in the Plane - Cabri Jr: Interactive

#### Activity Overview

In this activity, you will explore the invariant properties of rotations and the results of rotations in the coordinate 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
• 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 53 - 56 from the attached PDF file for your class
• #### During the Activity

Distribute the pages to your class.

• Use the AppVar to go directly to the exploration section
• Construct a triangle to rotate and a point that will be the center of rotation
• Construct a rotation angle tool
• Rotate the triangle using the tool
• Drag the sides and vertices of the triangle and points on the tool and observe the relationships between the pre-image and the image
• Construct a triangle on a coordinate axis to rotate
• Rotate the triangle and identify the coordinates of some vertices
• Form a counter-clockwise rotation, drag the vertice and look for patterns in the coordinates of the vertice and its image
• #### After the Activity

Review student results:

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