3.4 parallel Lines and the Triangle Angle-Sum Theorem

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3.4 parallel Lines and the Triangle Angle-Sum
Theorem

• 12.0 Students find and use measures of interior
  and exterior angles of triangles to classify
  figures and solve problems
• 13.0 Students prove relationships between angles
  in polygons by using properties of complementary,
  supplementary, vertical, and exterior angles

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Triangle Angle-Sum Theorem

• The sum of the measures of the angles of a
  triangle is 180

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Example 1
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Example 2
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Example 3
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Classifying Different Triangles
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Vocabulary

• Exterior angle of a polygon an angle formed by
  an side and an extension of an adjacent side

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Vocabulary

• Remote interior angle two nonadjacent interior
  angles

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Example 1
X
123
90
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Example 2
Z
57
57
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Example 3
35
20
X
Y
Z
43
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Assignment

• Pg 150 1-9, 20, 24, 26