Lesson 7­3 Similar Triangles with answers.notebook

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January 22, 2015

Questions/Main IdeasLesson 7-3 Similar Triangles

Postulate 6.1 Angle-Angle (AA) SimilarityIf two angles of one triangle are congruent to two angles of another triangle, then the triangles are similar.

Theorem 7.2 Side-Side-Side (SSS) SimilarityIf the corresponding side lengths of two triangles are proportional, then the triangles are similar.

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Lesson 7­3 Similar Triangles with answers.notebook

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January 22, 2015

Theorem 7.3Side-Angle-Side (SAS) SimilarityIf the lengths of two sides of one triangle are proportional to the lengths of two corresponding sides of another triangle and the included angles are congruent, then the triangles are similar.

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Example 1Determine whether the triangles are similar. If so, write a similarity statement. Explain your reasoning.a. b.

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Lesson 7­3 Similar Triangles with answers.notebook

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January 22, 2015

Example 2Determine whether the triangles are similar. If so, write a similarity statement. Explain your reasoning.a. b.

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Example 3If ΔRST and ΔXYZ are two triangles such that which of the following would be sufficient to prove that the triangles are similar?

Questions/Main IdeasRS 2XY 3

=

Lesson 7­3 Similar Triangles with answers.notebook

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January 22, 2015

Theorem 7.4Similarity of triangles is reflexive, symmetric, and transitive.

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Example 4Given RS // UT, RS = 4, RQ = x + 3, QT = 2x + 10, UT = 10, find RQ and QT.

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Lesson 7­3 Similar Triangles with answers.notebook

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January 22, 2015

Example 5Josh wanted to measure the height of the Sears Tower in Chicago. He used a 12-foot light pole and measured its shadow at 1 P.M. The length of the shadow was 2 feet. Then he measured the length of the Sears Tower's shadow and it was 242 at that time. What is the height of the Sears Tower?

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Lesson 7­3 Similar Triangles with answers.notebook

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January 22, 2015

Lesson 7­3 Similar Triangles with answers.notebook

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January 22, 2015