Download 7.3 Proving Triangles Similar.notebook

7.3 Proving Triangles Similar.notebook
March 21, 2014
Homework Review
Mar 21­8:56 AM
10­2 Proving Triangles Similar: AA, SAS, and SSS
Objective: Be able to use AA~ Postulate and the SAS~ and
SSS~ Theorems and to use similarity to find indirect measures
Angle­Angle Similarity Postulate (AA~ Postulate)
If two angles of one triangle are congruent to two angles of another triangle, then the triangles are similar.
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7.3 Proving Triangles Similar.notebook
March 21, 2014
Explain why the triangles are similar. Write a similarity statement.
Mar 18­8:39 AM
Indirect measurement: Using similar triangle and measurement to compute distance that are difficult to measure directly.
To find the height of a fire tower, Latisha places a mirror on the ground 40 ft from the base of the tower. Latisha's eyes are 5.5 ft above the ground. When Latisha stands 4 ft from the mirror, she can see the top of the tower. How tall is the fire tower?
A lamppost casts a 9­ft shadow at the same time a person 6 ft tall casts a 4­ft shadow. Use similar triangles to find the height of the lamppost.
Mar 14­9:18 AM
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7.3 Proving Triangles Similar.notebook
March 21, 2014
Theorem 10.1
Side­Angle­Side Similarity Theorem
If an angle of one triangle is congruent to an angle of a second triangle, and the sides including the two angles are proportional, then the triangles are similar.
Theorem 10­2
Side­Side­Side Similarity Theorem
If the corresponding sides of two triangles are proportional, then the triangles are similar.
What postulate or theorem proves the pairs of triangles similar?
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Mar 14­9:30 AM
Write a similarity statement and explain why the triangles are similar. Then find the length of DE.
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7.3 Proving Triangles Similar.notebook
March 21, 2014
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Homework:
pg. 456 ­ 457
#'s 18 ­ 20 all, 23 ­28 all
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