obj. 12 parallel lines
TRANSCRIPT
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Obj. 12 Parallel Lines
The student is able to (I can):
Identify parallel lines, perpendicular lines, skew lines, and parallel planes
Identify Identify
Transversals
Corresponding angles
Alternate Interior Angles
Alternate Exterior Angles
Same-side Interior Angles
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Parallel Lines
Perpendicular
Coplanar lines that do not intersect
Two coplanar lines that intersect at right
m
nm n
Perpendicular Lines
Two coplanar lines that intersect at right angles (90)
f
gf g
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Skew Lines
Parallel Planes
Noncoplanar lines that do not intersect
Planes that do not intersectParallel Planes Planes that do not intersect
RRRR
SSSS
Plane R Plane S
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transversal A line that intersects two coplanar lines at two different points
r
s
t
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corresponding angles
Lie on the same side of the transversal t, on the same sides of lines r and s
Example: 1 and 5
1 2
r t
87
65
431 2
s
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alternate interior angles
Nonadjacent angles that lie on opposite sides of the transversal t, between lines r and s
Example: 3 and 6
1 2r
t
8765
431 2
s
interior
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alternate exterior angles
Lie on opposite sides of the transversal t, outside lines r and s
Example: 1 and 8
1 2
r texterior
8765
431 2
sexterior
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same-side interior angles
Lie on the same side of the transversal t, between the lines r and s
Example: 3 and 5
312
r t
87
65
432
s
interior
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transversal
Corresponding angles are congruentCorresponding angles are congruent
876
54
312
1 52 63 74 8
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Alternate interior angles are congruent
Alternate exterior angles are congruent
87 65
4312
2 74 5
Alternate exterior angles are congruent
87
65
43
12
1 84 5
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Same-side interior angles are supplementary.
8765
431 2
87
m3 + m5 = 180m4 + m6 = 180
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1. Find the measures of the numbered angles
2. List each angle pair
corresponding angles
1 & 4; 2 & 5; 3 & 6; 8 & 7
1 2
3 125(8)
Practice
m1 = 125; m2 = 55;m3 = 55; m4 = 125;m5 = 55; m6 = 55; m7 = 125
3 & 6; 8 & 7alt. interior angles
3 & 5; 8 & 4alt. exterior angles
1 & 7; 2 & 6same-side interior angles
3 & 4; 8 & 5
4 56 7