Education Technology

# Activities

• ##### Subject Area

• Math: Geometry: Points, Lines and Angles

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

## Betweenness and the Sum of Parts

#### Activity Overview

In this activity, students' will explore the concepts of betweenness and the sum of parts visually, geometrically, and numerically for segments and angles using the Cabri® Jr. application. They will investigate how the sum of parts equals the whole.

#### 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
• 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 3 - 5 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
• Draw and label a segment and a point on the segment
• Measure the length of the segments
• Change the position of the point and observe the change in the measures and note how they are related
• Draw segments to form adjacent angles
• Measure the angles formed
• Change the position of the segment and observe the changes in the measures and note how they are related
• #### After the Activity

Review student results

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