Question about homework?

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Question about homework?

• Any questions on the homework? (choose random
  problems)

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7.3 Proving Triangles Similar
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Related Topic

• Remember we had to prove triangles congruent?
  Proving triangles similar is similar to proving
  triangles congruent but different
• The theorems to prove triangles similar are
  different

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Postulate 7.1 Angle-Angle similarity (AA)
Postulate

• If two angles of one triangle are congruent to
  two angles of another triangle, then the
  triangles are similar

P
T
R
S
L
M
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Theorem 7.1 Side-Angle-Side Similarity (SAS)
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
• Examples

Notice the difference
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Theorem 7.2 Side-Side-Side (SSS) Theorem

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

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Are the triangles similar? Why? Write the similar
statement
W
V
S
45
45
R
B
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Are the triangles similar? Why? Write the similar
statement
P
X
8
6
Z
Q
R
Y
4
3
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If the triangles are similar, find DE
A
12
10
B
24
D
C
16
18
E
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Vocabulary

• Indirect measurement You use similar triangles
  and measurements to find distances that are
  difficult to measure directly

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Example of indirect measurement
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Homework/Classwork

• Pgs 385-387 1,2, 4-20, 24-27, 32