Education Technology

# Activities

• ##### Subject Area

• Math: Geometry: Triangles

9-12

40 Minutes

• ##### Device
• TI-Nspire™ CX/CX II
• TI-Nspire™ CX CAS/CX II CAS
• TI-Nspire™
• TI-Nspire™ CAS
• ##### Software

TI-Nspire™
TI-Nspire™ CAS

3.0

• ##### Accessories

TI-GRAPH LINK™ Cable

## Proportional Segments

#### Activity Overview

The purpose of this activity is to investigate the relationship between segments formed by drawing a line parallel to one side of a triangle or by drwing and angle bisector of one the angles.

#### Before the Activity

Students should have a working knowledge of TI-Nspire. At the same time students should have an understanding of Side-Side-Side similarity theorem.

See attachments.

#### After the Activity

In closing the activity, the teacher should guide the students in discovering that, if a line parallel to one side of a triangle intersects the other two sides, then it divides the two sides proportionally. Also, if a ray bisects an angle of a triangle, then it divides the opposite side into two segments whose lengths are proportional to the lengths of the other two sides.