Journal 3'1

1
Journal 3.1

• Chapter 3 Section 1
• Lines and Angles

2
State Standards

• State Standard 7.0 Students prove and use
  theorems involving the properties of parallel
  lines cut by a transversal, the properties of
  quadrilaterals, and the properties of circles.
• State Standard 16.0 Students perform basic
  constructions
• ESLR I

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Sec. 1 Definitions
Parallel Lines coplanar lines that do not
intersect. (// lines)
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Skew Lines noncoplanar lines that are neither
parallel nor intersecting.

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Parallel Planes planes that do not intersect.
A line and a Plane can also be parallel.
Can ?
B
Only if
A
D
C
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Theorem
If two parallel planes are cut by a third plane,
then the lines of intersection are parallel.
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Transversal A line that intersects two or more
coplanar lines in different points.
exterior
exterior
interior
interior
exterior
exterior
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Alternate Interior Angles
1
4
2
3
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Alternate Exterior Angles
4
1
2
3
10
Consectutive interior angles
1
2
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Corresponding angles
1
2
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Questions
True/False A transversal intersects only
parallel lines.
True/False Skew lines are not coplanar.
True/False If two lines are coplanar then they
are parallel.
True/False If two lines are parallel then
exactly one plane contains them.
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Name the transversal
n
m
1
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n
m
l
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Parallel Postulate

• There is exactly one line through a point P
  parallel to a line l.

P
?
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Perpendicular Postulate

• There is exactly one line through a point P
  perpendicular to a line l.

?
P
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Class work Pg. 132 1-10
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Homework 3.1