Education Technology

# Activities

• ##### Subject Area

• Math: Geometry: Triangles

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

## Ratios in Right Triangles

#### Activity Overview

The study of properties of right triangles is a major topic in mathematics. In this activity, you will investigate three common right triangle trigonometric ratios.

#### 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 105 - 106 from the attached PDF file for your class
• #### During the Activity

Distribute the pages to your class.

Follow the Activity procedures:

• Construct a right triangle
• Measure the lengths of the sides of the triangle and the interior angles of the triangle
• Calculate the ratio of the length of sides and observe the effects of changing the measure of an angle or the length of a side
• #### After the Activity

Review student results:

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