1. Goal: The learner will us AA Similarity.
Lesson 6.4
Goal: The learner will us AA Similarity.

2. Equilateral Triangles
Are all equilateral triangles similar? Explain.

3. Angle-Angle (AA) Similarity
If 2 angles of one triangle are congruent ot 2 angles of another triangle, then they are similar.
J X
ΔJKL~ΔXYZ
Y Z
K L

4. Why don’t I need to know the measure of the third angle of the triangles?

5. Are They Similar? 64 64 26

6. Similar? T A S V 52
E B R U
D C

7. How could this possibly be useful?
Indirect measurement!
Similar triangles can be created and proportions setup to solve for missing measurements.

8. A flagpole casts a shadow that is 50 feet long
A flagpole casts a shadow that is 50 feet long. At the same time, a woman standing nearby who is 5’ 4” tall casts a shadow that is 40” long. How tall is the flagpole to the nearest foot?
p. 384 #3-17, 26-29, 31