Education Technology

# Activities

• ##### Subject Area

• Math: Geometry: Points, Lines and Angles
• Math: Geometry: Triangles

9-12

30 Minutes

• ##### Device
• TI-Nspire™ Navigator™
• TI-Nspire™
• TI-Nspire™ CAS
• ##### Software

TI-Nspire™
TI-Nspire™ CAS

2.0

• ##### Other Materials
By Michele Patrick

## Triangle Inequalities

#### Activity Overview

Students explore sides and angles of an isosceles triangle. In addition, for scalene triangles they explore that for a triangle, congruent angles are opposite of congruent sides. The largest angle is opposite the longest side, and the smallest angle is opposite the shortest side. Students are led to the fact that the measure of an exterior angle is greater than the measure of either remote interior angle. Students then discover facts by proof about perpendicular segments.

#### Key Steps

• Download the attached PDF and look over the information on the first page. Download and distribute the attached TI-Nspire document (.tns file) and student worksheet for use during the activity. A TI-Nspire document containing expected student results is also available for download.

• Discuss the material from the activity pages and worksheet with students as needed.

• Encourage students to summarize what they have learned from completing the activity.