Points, Lines, Segments, and Rays

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Points, Lines, Segments, and Rays

• Lesson 8-1

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Points
A point is a location in space. It has no size.
It is named by a capital letter.
.
Read it as Point A
Write it as A
A
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Lines
A line is a series of points that extends in two
opposing directions without end. Lines have no
thickness.
Q
S
Read it as Line QS or Line SQ
Write it as
QS
or
SQ
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Segments
A segment is a part of a line with two endpoints.
R
B
Read it as Segment RB or Segment BR
Write it as
RB
or
BR
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Rays
A ray consists of an endpoint and all the points
of a line on one side of the endpoint.
C
D
Read it as Ray CD (the order does matter)
Write it as
CD
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Collinear and Noncollinear Points

• Points that are on the same line are called
  collinear points.
• If a single line cannot be drawn through all the
  points, then the points are noncollinear.

W
U
E
F
C
D
X
V
Collinear points
Noncollinear points
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Planes
A plane is a flat surface with no thickness that
extends without end in all directions.
Intersecting lines are lines that cross
(intersect) at exactly one point.
Parallel lines are lines that do not cross (they
have no points in common).
Skew lines are not parallel and they do not
intersect. They lie in different planes.
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Homework Time