Education Technology

# Activities

• ##### Subject Area

• Math: Geometry: Similarity and Proportion

9-12

30 Minutes

• ##### Device
• TI-Nspire™
• TI-Nspire™ CAS
• TI-Nspire™ CX/CX II
• TI-Nspire™ CX CAS/CX II CAS
• TI-Nspire™ Apps for iPad®
• ##### Software

TI-Nspire™
TI-Nspire™ CAS

3.9

## Applications of Similar Figures

#### Activity Overview

Students will identify corresponding parts of figures and use the definition of similar figures to solve real-world applications involving rectangles and triangles.

#### Objectives

• Students will identify corresponding parts of similar figures.
• Students will apply what they know about similar figures to solve real-world design problems.

#### Vocabulary

• similar
• corresponding parts

#### About the Lesson

In this lesson, students use similar figures to solve real-world applications. In Problem 1, students use similar rectangles to enlarge a photo. In Problem 2, students use similar triangles to estimate the height of a building.

As a result, students will:

• Use the definition of similarity to decide if two figures are similar.
• Model with geometry and apply the principle of similar figures to solve design problems.
• Explain the meaning of similarity for triangles as the equality of all corresponding pairs of angles and the proportionality of all corresponding pairs of sides.