CPREP - Chapter 8 Packet Answers
8.1 Warm Up
For use before Activity 8.1
1. 24 m
2. 40 cm
3. 36 yd
9. yes; The diameter of each of the small circles in
diagram B is 2 feet. Because there are 5 circles
along each side of the square, the length of each
side is 5  2  10 feet.
4. 120 ft
10.about 9.6 times
5. 16 in.
6. 60 mm
8.1 Start Thinking!
For use before Lesson 8.1
Sample answer: The circumference of a tree trunk is
easier to measure. Unless the tree is cut down, you
do not have access to the circular cross section in
order to measure the diameter. The diameter of a
quarter is easier to measure. You only need a ruler
to measure across the quarter. In general, it is
usually easier to measure the diameter of a circular
object. The circumference is easier to measure only
when you cannot access the diameter to measure it.
8.1 Puzzle Time
HE HAD TOO MUCH TIME ON HIS HANDS
8.1 Warm Up
For use before Lesson 8.1
1. about 37.68 in.
2. about 12.56 ft
8.2 Warm Up
For use before Activity 8.2
1. 16 cm
2. 17 ft
3. 52 in.
3. about 22 cm
4. about 62.8 ft
4. 25 m
5. about 44 mm
6. about 3.14 in.
8.2 Start Thinking!
For use before Lesson 8.2
Sample answer: yes; It is made up of a rectangle and
two semicircles. Some examples: windows
(rectangle and semicircle), some company and
organization logos, a first place ribbon (circle and
rectangles), some flowers
8.1 Practice A
1. 30 ft
2. 4 m
3. 32 mm
4. 5 cm
6. 3.5 yd
5. 12 in.
7. about 53.38 m
8. about 18.84 ft
9. about 88 in.
10. about 56.54 mm
11.about 20.56 in.
12. about 25.7 yd
13.a.8 mm; 24 mm
b. 3 times greater
14.
$131.56 15.
about 5.14 ft
8.1 Practice B
1. about 81.64 m
2. about 37.68 ft
3. about 264 in.
4. about 72 yd
5. about 31.05 ft
6. about 28.27 cm
7. Circle
8.2 Start Thinking!
For use before Activity 8.2
Sample answer: To find the perimeter of an
irregular shape, you can add all of the different
straight sections (or circular sections). To find a
distance on a map, assuming that the route traveled
is not along a straight line, you must add all of the
straight sections to estimate the total distance.
5. about 56.52 in. 6. about 62.8 ft
8.2 Warm Up
For use before Lesson 8.2
1. 24 units
2. 24 units
3. about 15 units
4. about 13.71 units
5. about 20.5 units
6. about 22.28 units
8.2 Practice A
1. about 24 in. 2. about 28 in. 3. about 21.42 in.
4. 34 yd
5. 24 in.
6. 60 mm
7. 31 m
8. 24 ft
9. 64 cm
A
B
C
D
10.about 23.42 ft
Radius
2.5 ft
1 ft
32 ft
3.5 ft
Diameter
60 in.
24 in.
768 in.
84 in.
8.2 Puzzle Time
LIBRARY
8. about 9.42 in.
11. $3685.90
CPREP - Chapter 8 Packet Answers
8.3 Start Thinking!
For use before Activity 8.3
Sample answer: 1. You can divide it into several
triangles each with a vertex at the center of the
circle.
2. You can put it on grid paper and estimate the
number of squares that are covered. 3. You can
divide
it into tall, narrow rectangles.
8.3 Warm Up
For use before Activity 8.3
8.3 Puzzle Time
HAMWORK
8.4 Start Thinking!
For use before Activity 8.4
Answers will vary. Sample answer: If you are
planning on painting a room, you will need to
calculate the area of each section of wall to figure
out how much paint to buy. The windows and
doorways make some walls composite figures.
1. 63 in.2
2. 14 m 2
3. 66 yd 2
8.4 Warm Up
1. 100 ft 2
2. 256 in.2
4. 50 cm2
5. 22.4 m2
6. 1 mm 2
3. 150 m2
4. 30 cm2
5. about 314 ft 2
6. about 7850 yd 2
8.3 Start Thinking!
For use before Lesson 8.3
Sample answer: It is easier to use
22
7
if the radius
is a multiple of 7. It is easier to use 3.14 in all other
instances.
8.3 Warm Up
For use before Lesson 8.3
1. about 50.24 in.2
2. about 154 ft 2
3. about 3.14 cm2
8.4 Start Thinking!
For use before Lesson 8.4
Check students’ drawings and calculations.
8.4 Warm Up
For use before Lesson 8.4
1. 21 units2
2. 20 units2
3. 12 units2
4. about 12.53 units2
5. 18 units2
6. about 17.72 units2
8.3 Practice A
1. about 78.5 m2
2. about 7850 mm
8.4 Practice A
1. 30 units2
2. 33 units2
3. about 1256 in.2
4. about 38.5 ft 2
4. 48 in.2
5. about 178.5 mm2
5. about 1386 mm2
6. about 3850 cm2
6. 402 ft 2
7. 210 cm2
7. about 50.24 ft 2
8. about 15,400 cm2
8. 60 yd 2
9. 40 m2
9. about 113.04 in.2
11.
99
in.2
224
2
10. about 28.26 in.2
12.
about 153.86 in.2
3. 16 units2
10.perimeter: about 37.85 ft; area: about 69.625 ft 2
11.
a. 144 in.2
b. 72 in.2
c. $172.80
8.4 Puzzle Time
DO WE WALK OR HOP ON A DO