What

1
Whats Your Angle?

• By Kim Davis

2
Background Vocabulary

• Plane an infinite, flat surface.
• Parallel lines lines in a plane that never meet.
  l l is the symbol for parallel lines.
• Transversals lines that intersect two or more
  parallel lines.

3
More Vocabulary

1. Congruent angles two angles that have equal
   measures.
2. Ray part of a line that has an endpoint and
   extends forever.
3. Angles two rays with a common endpoint.

4
Types of Angles

• Acute angles that measure less that 90.

5

• Right angles that measure 90.

6

• Obtuse angles that measure more than 90 and
  less than 180

7

• Straight angles that measure 180.

8
Complementary Angle
Two angles whose measure add up to 90.
45
45
9
Supplementary Angles
Supplementary Angles

• Two angles whose
• measures add up
• to 180.

Two angles whose measures add up to 180.
90
90
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Congruent Angles

• When a transversal
• intersects two parallel
• lines, eight angles are
• formed.

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2.
1.
3.
4.
5.
6.
7.
8.
12
Alternate Interior Angles
2.
1.
3.
4.
5.
6.
7.
8.
Angle 3 and Angle 6 are congruent angles. This
means they have the same measure.
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Alternate Interior Angles
2.
1.
3.
4.
5.
6.
7.
8.
Angle 4 and Angle 5 are congruent angles.
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RECAP SO....

• The measure of angle 4 and the
• measure of angle 6 are congruent
• AND
• The measure of angle 3 and the
• measure of angle 5 are congruent.

15
NOTE

• Alternate Interior Angles are on alternate
  sides and on the interior of the parallel lines.

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Vertical Angles
2.
1.
3.
4.
5.
6.
7.
8.
Angle 1 and Angle 4 are congruent angles.
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Vertical Angles
2.
1.
3.
4.
5.
6.
7.
8.
Angle 2 and Angle 3 are congruent angles.
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Vertical Angles
2.
1.
3.
4.
5.
6.
7.
8.
Angle 5 and Angle 8 are congruent angles.
19
Vertical Angles
2.
1.
3.
4.
5.
6.
7.
8.
Angle 6 and Angle 7 are congruent angles.
20
RECAP

• The measures of Angle 1 and Angle 3 are
  congruent.
• The measures of Angle 2 and Angle 4 are
  congruent.
• The measures of Angle 5 and Angle 7 are
  congruent.
• The measures of Angle 6 and Angle 8 are
  congruent.

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NOTE

• Vertical Angles are diagonally across from each
  other.

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Corresponding Angles

• These angles are a bit trickier. You have to
  imagine cutting your diagram apart, and then
  pasting one part on top of the other.

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Corresponding Angles
2.
1.
3.
4.
5.
6.
7.
8.
Angle 1 and Angle 5 are congruent angels.
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Corresponding Angles
2.
1.
3.
4.
5.
6.
7.
8.
Angle 2 and Angle 6 are congruent.
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Corresponding Angles
2.
1.
3.
4.
5.
6.
7.
8.
Angle 3 and Angle 7 are congruent angles.
26
Corresponding Angles
2.
1.
3.
4.
5.
6.
7.
8.
Angle 4 and Angle 8 are congruent angles.
27
RECAP

• Angle 1 and Angle 5 are congruent.
• Angle 2 and Angle 6 are congruent.
• Angle 3 and Angle 7 are congruent.
• Angle 4 and Angle 8 are congruent.

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Demonstrate Your Knowledge

• Now that youve seen what is
• congruent, you can take the
• measurement of 1 angle and figure
• out the others. Lets try it!

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Angle 2 measures 110. What do the other angles
measure?
2.
1.
3.
4.
5.
6.
7.
8.
WHY??