6th Grade Math Textbook, Fundamentals

Lesson 9-5 for exercise sets. &KDSWHU 

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Use the diagram at the right.

1.Name 2 pairs of congruent line segments.

2.Name 2 pairs of congruent angles.

Make the following constructions using a compass and straightedge.

3.Draw an angle and bisect it. 4.Draw a line segment and its

perpendicular bisector.

5.Discuss and Write Explain how to use string, chalk, and a straightedge to bisect

the angle formed by two adjacent walls that meet at a corner of your classroom floor.

You can use a compass and a straightedge to bisect an angle.

Follow these steps to bisect angle MNO.

You can use a compass and a straightedge to construct

the perpendicular bisector of a line segment. Construct the

perpendicular bisector ofAB.

P O

M N

With the compass tip

at vertex N, draw an

arc intersecting NM

and NO. Label the

points of intersection

as A andB.

Open the compass further. With

the compass tip on A, draw an arc.

With the same compass opening

and the tip on B, draw another arc

intersecting the first arc. Label the

point of intersection C.

With your straightedge,

draw a ray from vertex

N through C.

NCbisects MNO.

MNCONC

O

A

M

N B O

A C

M

N B O

A C

M

N B

O

M

N

AB

With the compass tip

on point A, construct

an arc that will extend

both above and below

AB. Be sure the opening

is greater than AB.

AB

1

2

With the same setting as in

Step 1, put the compass tip

on B, and construct an arc

that will extend above and

below the line segment. Label

the points where the two arcs

intersect as Xand Y.

AB

X

Y

Use a straightedge to

draw XY. Label the point

of intersection of ABand

XYas M. XYis the

perpendicular bisector

of AB. Point Mis the

midpoint of AB.

A

M

B

X

Y