Points, Lines, and Planes

1
Lesson 1.2
Date ___/___/___

• Points, Lines, and Planes

Objective1 to understand the basic terms of
geometry Objective 2 to understand the basic
postulates of geometry
2
Some vocab we need

• Point
• a specific location
• has no size
• represented by a small dot
• named by a capital letter

3

• Space
• the set of all points

4

• Line
• a series of points that extends forever in both
  directions
• named by any 2 points on the line
• named by a single lower case letter

5

• Collinear points
• points that lie on the same line

6

• Plane
• a flat surface that has no thickness
• Contains many lines
• Extends without end in all directions
• Named by single capital letter
• Named by 3 noncollinear points

7

• Coplanar
• points and lines in the same plane

8

• Postulate or axiom
• accepted statement of fact

9
Postulate 1.1

• Through any two points there is exactly one line.

10
Postulate 1.2

• If two lines intersect, then they intersect in
  exactly one point.

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Postulate 1.3

• If two planes intersect, then they intersect in
  exactly one line.

12
Postulate 1.4

• Through any 3 noncollinear points there is
  exactly one plane.

13
CU 1
In the figure below, name 3 collinear points and
3 noncollinear points.
14
CU 2
Name the plane shown in two different ways.
15
CU 3
What is the intersection of plane HGC and plane
AED?
..
16
CU 4
Shade the plane that contains X, Y, and Z.
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Tonights Assignment

• Lesson 1.2
• 2, 6, 10, 14, 20, 22, 30, 35, 36, 38, 40, 46