Geometry 3-1 Parallel Lines and Angles

1
Geometry 3-1 Parallel Lines and Angles

• Parallel Lines- lines that never intersect
• Symbol
• Perpendicular Lines- lines that intersect and
  make right angles
• Symbol -
• Parallel Planes- planes that do not intersect
• Skew lines- lines that are not coplanar, are not
  parallel, and do not intersect.

2
Examples
Identify each of the following.
a. a pair of parallel segments
BF EJ
b. a pair of perpendicular segments
BF - FJ
c. a pair of skew segments
BF and CD
3
Vocabulary

• Transversal A line that intersects two lines at
  different points.

Transversal line
Exterior
Interior
Exterior
4
Vocabulary

• Corresponding angles the same angle location but
  for a different intersection.

congruent
B
A
C
D
B
A
C
D
5
Vocabulary

• Alternate Interior Angles opposite sides of the
  transversal and between the parallel lines.

congruent
B
A
A
B
6
Vocabulary

• Alternate Exterior Angles opposite sides of the
  transversal and outside the parallel lines.

congruent
A
B
A
B
7
Vocabulary

• Same-Side Interior same side of the transversal
  and between parallel lines.

supplementary
A
B
A
B
8
Vocabulary

• Same-Side Exterior Angles same side of the
  transversal and outside the parallel lines.

supplementary
B
A
A
B
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