Sec' 1 4 Segments, Rays, Parallel Lines and Planes

1
Sec. 1 4 Segments, Rays, Parallel Lines and
Planes

• Objectives
• 1) Identify segments and rays.
• 2) Recognize parallel lines.

2

• Line A series of points that extend in 2
  directions without end.
• Notation 2 capital letters with a line over
  them.
• Ex
• Reads Line AB

AB
A
B
3

• Segment Is the part of a line consisting of two
  endpoints all the points between them.
• Notation 2 capital letters with a line over
  them.
• Ex
• No arrows on the end of a line.
• Reads Line segment (or segment) AB

AB
A
B
4

• Ray Is the part of a line consisting of one
  endpoint all the points of the line on one side
  of the endpoint.
• Notation 2 capital letters with a line with an
  arrow on one end of it. End point always comes
  first.
• Ex
• Reads Ray AB

AB
A
B
5
Same Line

• Opposite Rays Are two collinear rays with the
  same endpoint.
• Opposite rays always form a line.
• Ex

RQ RS
S
Q
R
Endpoints
6
Ex.1 Naming segments and rays.
L
P
Q

• Name 3 segments
• LP
• PQ
• LQ

• Name 4 rays
• LQ
• QL
• PL
• LP
• PQ

Are LP and PL opposite rays?? No, not the same
endpoints
7

• Parallel Lines Are coplanar lines that never
  intersect.
• Coplanar same plane
• Symbol //
• Ex r // t
• Reads line r is parallel to line t.

r
t
8

• Skew Lines Are noncoplanar lines that never
  intersect.
• Skew lines are never //
• Parallel Planes Are planes that do not
  intersect.

E
A
H
D
F
B
G
C
9
What have we learned??

• Name the following line.
• Name a segment.
• Name a ray.

XY or YZ or ZX
Z
XY or YZ or XZ
Y
XY or YZ or ZX or YX
X
10

1-3