Download Section 1-1: Understanding Points, Lines, and Planes 3 Undefined

Name _____________________
Date _________
Period ________
Section 1-1: Understanding Points, Lines, and Planes
3 Undefined Terms in Geometry
 Point:
 Line:
 Plane:
Segment:
_________________________________________________
Ray:
___________________________________________
Opposite Rays:
__________________________________________
__________________________________________
• A __________ names a location and has no size. •P
• A ________ is a straight path that extends forever in two directions.
• A ___________ is a flat surface that extends forever.
• A _______________ is part of a line and consists of two points and
all the points in between.
• An ________________ is a point at the end of a segment or a ray.
• A ______ is a part of a line that starts at an endpoint and
extends forever in one direction.
A point has no size. It is named using a capital letter.
All the figures below contain points.
Figure
line
Characteristics
Diagram
•P
point P
Words and Symbols
___ endpoints
extends forever
in two directions
________ ____
or
____
line segment ___ endpoints
or segment has a finite
length
______________
____
or
____
ray
___ endpoint
______ ____
or
____
A ray is named
starting
with its endpoint.
extends forever
in one direction
plane
extends
forever
in all
directions
plane ______
or
plane ___
Identify the following.
1.
•Y
2.
_______________
4.
3.
_____________
5.
_____________
_____________
6.
_____________
_____________
Answer each question.
7. How are a line and a line segment different?
_________________________________________________
8. How are a line segment and a ray different?
_________________________________________________
Intersection:
___________________________________________
__________________________________________
Term
Collinear
Meaning
points that lie on the
___________ line
Model
Noncollinear
points that do
________ lie on the
same line
F and G are ___________________
Coplanar
points or lines that lie in
the same
____________
Noncoplanar
Points or lines that do
_______ lie in the
same plane
F, G, and H are ________________
W, X, and Y are ____________.
W, X, Y, and Z are __________.
Figures that intersect share a common set of points.
In the first model above, ⃡𝐹𝐻 intersects ⃡𝐹𝐺 at __________ ____.
⃡ intersects plane WXY at __________ ____.
In the second model, 𝑋𝑍
Draw and label a diagram for each figure.
1. point W
2. line MN
3.
4. 𝐸𝐹
JK
Name each figure using words and symbols.
5.
6.
________________________
_____________________
Name the plane in two different ways.
7.
8.
________________________
_____________________
Use the figure for Exercises 9–14.
Name each of the following.
9. three collinear points
____________________
10. three noncollinear points
____________________________
11. four coplanar points
____________________
12. four noncoplanar points
____________________________
13. two lines that intersect ⃡𝐶𝐷
____________________
14. the intersection of ⃡𝐽𝐾 and plane R
____________________________
A __________________ is a statement that is accepted as true without
proof.
Postulates: Points, Lines, and Planes
Through any two points there is exactly one
line.
Through any three noncollinear points there is
exactly one plane containing them.
If two poins lie in a plane, then the line
containing those points lie in the plane.
Postulates: Intersection of Lines and Planes
If two lines intersect, then they intersect in
exactly one point.
If two planes intersect, then they intersect in
exaclty one line.