# Activities

• • • ##### Subject Area

• Math: Geometry: Triangles

• ##### Author 9-12

40 Minutes

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

TI-Nspire™
TI-Nspire™ CAS

2.0

• ##### Other Materials
By Karen Campe

## Angle Bisectors in a Triangle #### Activity Overview

In this activity, students will explore the relationships between an angle bisector and segments in a triangle. They will determine the distances from an angle bisector to the sides of the bisected angle. In a triangle, proportional relationships occur when an angle bisector divides the opposite side into two parts.

#### Key Steps

• First, students will investigate the Angle Bisector Theorem. Students should see that the angle bisector is equidistant from both sides of the angle.

• Next, students will explore an angle bisector in a triangle. Students should see the relationships between the sides of the triangle and the bisector.

• As an extension, students will explore the incenter of a triangle.