8-1Points-LineSeg-Rays22222222222222.ppt

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1. Points, Lines, Segments, and
Rays
Lesson 8-1

2. Points
A point is a location in space. It has no size.
It is named by a capital letter.
.
A
Read it as: “Point A”
Write it as: “A”

3. 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:
QSorSQ

4. 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:
RBorBR

5. 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

6. 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.
CDEF
Collinear points
U
V
W
X
Noncollinear points

7. 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.

8. Homework Time