Parallel Lines and Transversals

1
Parallel Lines and Transversals

• Lesson 3.3

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Definition of transversal
Transversal a line that intersects a pair of
lines.
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Definition of transversal
1 2
3 4
5 6
7 8
The transversal creates 8 angles
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Alternate Interior Angles
1
2
3
4
5
6
7
8
Angles between the pair of lines on opposite
sides of the transversal
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Alternate Exterior Angles
1
2
3
4
5
6
7
8
Angles outside the pair of lines on opposite
sides of the transversal
6
Same Side Interior Angles
1
2
3
4
5
6
7
8
Angles between the pair of lines on same side of
the transversal
7
Corresponding Angles
1
2
3
4
5
6
7
8
Angles in the same relative position to the
transversal
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Corresponding Angle Postulate
If two lines cut by a transversal are parallel,
then the corresponding angles are congruent
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Alternate Interior Angle Theorem
If two lines cut by a transversal are parallel,
then alternate interior angles are congruent.
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Alternate Exterior Angle Theorem
If two lines cut by a transversal are parallel,
then alternate exterior angles are congruent.
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Same Side Interior Angle Theorem
If two lines cut by a transversal are parallel,
then the same-side interior angles total 180
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assignment

• P159 9 - 33