CK-12 Geometry - Second Edition

http://www.ck12.org Chapter 7. Similarity

7.3 Similarity by AA

Learning Objectives

• Determine whether triangles are similar.


• Understand AA for similar triangles.


• Solve problems involving similar triangles.

Review Queue

1. a. Find the measures ofxandy.
   b. The two triangles are similar. Findwandz.


2. Use the true proportion^68 = 28 x=^27 y to answer the following questions.

a. Findxandy.

b. Write another true proportion.

c. Is^288 =^612 +xtrue? If you solve forx, is it the same as in part a?

Know What?George wants to measure the height of a flagpole. He is 6 feet tall and his shadow is 10 feet long. At
the same time, the shadow of the flagpole was 85 feet long. How tall is the flagpole?