LESSON 8.3: Similar Polygons

OBJECTIVES: To use AA, SAS, and SSS Similarity Statements To apply AA, SAS, and SSS SimilarityStatements

Vocabulary and Key Concepts

Angle-Angle Similarity Postulate (AA ) Postulate _____________

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: If two angles of one triangle are congruent to two angles of another triangle then the two triangles are similar.

V : VTRS PLM

Using AA Similarity Postulate

MX AB Explain

why the triangles

are similar. Write a similarity statement.

: ___ ___ AMX BKX

Theorem 8-1: Side-Angle-Side Similarity (SAS ) Theorem

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___________________________.

:If two sides of one triangle are proportional to two sides of another triangle, and the included angle in one triangle is congruent to the included angle in the other triangle, then the two triangles are similar.

Theorem 8-2: Side-Side-Side Similarity (SSS ) Theorem______

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If the corresponding sides of two triangles are proportional, then the two triangles are similar.

:

USING SIMILARITY THEOREMS

Is ? Explain.

:V V VWX VYZ

Indirect measurement is _______________________________________________________________________________________________________________.

the

measurement of very large objects or of long distances (which are often made indirectly), using similar triangles and proportions

Indirect Measurement with Similar Triangles

Indirect Measurement with Similar Triangles

I ♥ Geometry!

Alex Giulano’s eye is 168 cm above the ground while he is standing 114 cm from the mirror. If the mirror is 570 cm from the flagpole, how tall is the flagpole?

FINAL CHECKS FOR UNDERSTANDING

1. You want to prove that by the SSS Theorem. Complete

the proportion that is needed to use

thistheorem.

FH = a = FGb = XS = c

V : VFHG RXS

FINAL CHECKS FOR UNDERSTANDING

Name a postulate or theorem that can be used to prove that the two triangles are similar. Then, write a similarity statement.

: ___ ___

A J 60 30 30

K L 60B C

Homework