Triangle Inequality Theorem

Author

Texas Instruments

Alignment

Standards Alignment

Textbook Alignment

Subject Area

Math: Geometry: Triangles

Level

9-12

Activity Time

90 Minutes

Software

TI Connect™

TI Calculator

TI-83 Plus Family

TI-84 series

Applications

Cabri™ Jr. for TI-83 Plus and TI-84 Plus

Other Materials

This is Activity 14 from the EXPLORATIONS Book:
Cabri Jr.: Interactive Geometry Activities and Investigations.

Resource Types

Lessons

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Triangle Inequality Theorem

Activity Overview

In this activity, students will explore the concepts underlying the Triangle Inequality Theorem by comparing side lengths and angle measures of a triangle. They will use an interactive construction to see why this theorem is true.

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 91 - 93 from the attached PDF file for your class

During the Activity

Distribute the pages to your class.

Follow the Activity procedures:

Use the AppVar to go directly to the exploration section

Draw a triangle and measure its angles and sides

Observe the relationship between the angle measures and the length of the side opposite the angle

Construct a special triangle with its first vertex as the center of a circle, its second vertex as a point within the circle, and its third vertex as a point on the circle

Observe the relationship among the three sides of a triangle

After the Activity

Review student results:

As a class, discuss questions that appeared to be more challenging

Re-teach concepts as necessary

Download Files

Download All Files (ZIP)

Before the Activity Files

Teacher Notes Appendix A PDF Teacher Notes Appendix B PDF Teacher Notes PDF CBIG1401.8xv CBIG1402.8xv

Author

Texas Instruments

Alignment

Standards Alignment

Textbook Alignment

Subject Area

Math: Geometry: Triangles

Level

9-12

Activity Time

90 Minutes

Software

TI Connect™

TI Calculator

TI-83 Plus Family

TI-84 series

Applications

Cabri™ Jr. for TI-83 Plus and TI-84 Plus

Other Materials

This is Activity 14 from the EXPLORATIONS Book:
Cabri Jr.: Interactive Geometry Activities and Investigations.

Resource Types

Lessons

Report an Issue

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Triangle Inequality Theorem

Cabri™ Jr. for TI-83 Plus and TI-84 Plus

Triangle Inequality Theorem

Before the Activity Files

Cabri™ Jr. for TI-83 Plus and TI-84 Plus

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