6th Grade Math Textbook, Fundamentals

Lesson 9-1 for exercise sets. &KDSWHU 

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Name and write the symbol for each figure.

Identify the figures in the diagram.

5.five points 6.four rays

7.eight line segments 8.two perpendicular lines

9.eleven angles

10.Discuss and Write Compare and contrast lines and rays; parallel and

perpendicular lines; and lines and planes.

D

E

F

Q

P

T

SR

C

P

Planes may or may not intersect. In the illustrated three-

dimensional figure above, plane ABFEand plane DCGHare

. In the same figure, plane ABFEand plane
ADHEare. In the illustrated three-
dimensional figure at the right, plane LKNOand plane JKNM
are intersecting planesthat are not perpendicular.

perpendicular planes

parallel planes

K

L

J

N

O

M

U

S R

T

Q

Figure Definition Read/Write

Coplanar lines are either intersectingor parallel.

Two lines that cross at exactly one point are

intersecting lines.

D

B

C

A

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Lines ABand CDintersect at right angles. (A right

angle has the shape of a corner of this page.) Lines

ABand CDare .perpendicular lines

AB ⊥CD

“is

perpendicular

to”

B

F

D C

A

H G

E

In the figure at the left, AB andEF are in the same

plane, but do not intersect. They are. In

the same figure, AB andCG are in differentplanes.

They are skew lines. lie in different planes

and are neither intersecting nor parallel.

Skew lines

parallel lines

AB EF

“is parallel to”