1'3 Points, Lines, and Planes

1
1.3 Points, Lines, and Planes

• A point has no dimension. Represented by a
  small dot.
• Ex. point A
• A line has one dimension. Extends without end
  in two directions. Is represented with two
  arrowheads.
• line l or

A
l
B
C
2
Planes

• A plane has two dimensions. Represented by a
  shape that looks like a floor or wall. Have to
  imagine that it extends without end.
• plane M or plane DEF

F
D
E
M
3
Postulate 1 Two Points Determine a Line

• Postulates statements that are accepted without
  further justification.
• Postulate 1 Two Points Determine a Line
• Through any two points there is exactly one line.
• Line n passes through points P and Q.

Q
n
P
4
Postulate 2 Three Points Determine a Plane

• Through any three points not on a line there is
  exactly one plane.
• Plane T passes through points A, B, and C.

B
A
C
T
5
Name Points, Lines, and Planes

• Use the diagram to
• a. Name three points
• b. Name two lines
• c. Name two planes
• Answers
• D, E, and F are points.
• Line m and line p.
• Q and R are planes.

p
D
E
m
F
Q
R
6

• Collinear points points that lie on the same
  line.
• Coplanar points points that lie on the same
  plane.
• Coplanar lines lines that are on the same plane.

7
Name Collinear and Coplanar Points

• Use the diagram to
• a. Name three points that are collinear.
• b. Name four points that are coplanar.
• c. Name three points that are not collinear.
• Solutions
• Points D, E, and F
• Points D, E, F, and G
• Points H, E, and G

H
F
E
D
G
8
Practice!

• Textbook p. 15 1 5 odd

9

• Segment - consists of two endpoints
• AB
• Ray consists of just one endpoint
• AB

B
A
B
A
10
Lines, Segments, and Rays
A
B
B
A
B
A
A
B
11
More Practice!!!

• Textbook p. 17 15 25 odd, 27 53 odd.
• Homework p. 17 18 16 52 even due FRIDAY!!