Name ———————————————————————
Date ————————————
Practice A
LESSON
11.6
For use with pages 792–799
Find the measure of a central angle of a regular
polygon with the given number of sides. Round
answers to the nearest tenth of a degree,
if necessary.
1. 12 sides
2. 16 sides
To find the measure of a central angle,
divide 360° by thenumber of sides.
3.
40 sides
Match the given angle measurement of the regular polygon to the correct
measurement.
4. m∠EGD
A 120°
5. m∠EGH
B 60°
6. m∠GHD
C 30°
7. m∠FGD
D 90°
A
B
F
G
E
H
C
D
8. What is the length of the apothem (the distance from the center to any side of the
polygon) of a regular hexagon with radius 7 inches? Round your answer to the
nearest tenth. (Hint: a hexagon has 6 sides.)
9. What is the length of the apothem of a regular octagon with diameter 18 feet?
Round your answer to the nearest tenth. (Hint: an octagon has 8 sides.)
1
Find the area of the regular polygon. Area of a regular polygon = }
aP,
LESSON 11.6
Copyright © Holt McDougal Math. All rights reserved.
2
when a is the length of the apothem and P is the perimeter. You can
1
also use: }
(number of sides • length of a side • apothem).
2
10.
11.
12.
13.
6.5
8
6
12
Geometry
IDEA! Works
239
Name ———————————————————————
LESSON
11.6
Practice A
continued
For use with pages 792–799
Date ————————————
LESSON
0.0
14. What is the area of a regular decagon with a side length of 6 meters? Round your
answer to the nearest tenth, if necessary. (Hint: a decagon has 10 sides.)
15. What is the area of a regular dodecagon with a side length of 9 centimeters?
Round your answer to the nearest tenth, if necessary. (Hint: a dodecagon has
12 sides.)
Find the perimeter and area of the regular polygon. Round answers to the
nearest tenth, if necessary.
16.
17.
18.
Decide whether the following statement is true or false.
19. As the number of sides of a regular polygon increases, the measure of the central
angle also increases.
20. The radius of a regular polygon is always greater than the apothem.
240
a perimeter of about 99.2 inches and a height of 30 inches.
a. What is the measure of each central angle?
b. Find the apothem, radius, and area of the stop sign.
Geometry
IDEA! Works
STOP
Copyright © Holt McDougal Math. All rights reserved.
LESSON 11.6
21. Stop Sign The stop sign shown is a regular octagon with
Quiz 1
Lesson 11.7
2
1. 80 m
2. 75 mm
3. 9 4. 6 5. 8 : 9; 64 : 81
ANSWERS
Lesson 11.4
Practice A
1. about 43.98 cm 2. about 62.83 ft
Practice A
3
1
1. } ; 0.5; 50% 2. } ; 0.375; 37.5%
2
8
3
1
3. } ; 0.25; 25% 4. } ; 0.75; 75% 5. 50%
4
4
6. about 21.46% 7. 80% 8. about 17.65%
18
29
3. about 7.64 in. 4. } m 5. } ft
π
π
9. 50% 10. 25% 11. 37.5%
6. 30π cm 7. about 11 in. 8. about 12.57 ft
12. 70 square units 13. about 39.8%
9. 3208 10. 1608 11. about 22.34 in.
14. about 60.2% 15. 25% 16. 25%
12. about 11.17 in. 13. about 23.56 cm
17. about 47.64% 18. 25% 19. 25%
14. 90 in. 15. 30, 28.27, 14.135, 58.27
20. about 38.9% 21. about 8.3% 22. 10%
16. 3.14; 1108; 8.5; 5; 808; 53.15
Problem Solving Workshop:
Mixed Problem Solving
17. a. about 14.14 in. b. 177 ft 18. 16 in.
1. a. 20% b. 80% 2. a. 15 in., 10 in.
b. 94.25 in., 62.83 in. c. about 4.24 revolutions,
Lesson 11.5
5. about 28.27 cm2; about 84.82 cm2 6. about
603.19 ft2; about 1206.37 ft2 7. about 62.86 m2
8. about 2.91 ft 9. B 10. A 11. C
12. D 13. about 37.7 in.2 14. about 21.46 cm2
15. about 25.13 in.2 16. 24 in.; about 113.10 in.2
about 6.37 revolutions
3. 132.73 in.2, 40.84 in.; 530.93 in.2, 81.68 in.;
Doubling the radius quadruples the area of the
circle because you are substituting 2r for r in the
equation for the area of a circle. Doubling the
radius doubles the circumference because you
are substituting 2r for r in the equation for the
circumference of a circle. 4. Answers will vary.
5. a. about 494.8 mi b. 9.63 mi;
Quiz 2
Quiz 3
Practice A
2
1. 4π in. ; 12.57 in.
2
2
2
2. 64π ft ; 201.06 ft
3. about 4.30 in. 4. about 11.62 cm
1. 37.7 m 2. 9.16 in. 3. 4.54 ft 4. 3π and 15π
1. 288.5 ft2 2. 534.5 cm2 3. 665.1 in.2
5. 56.55 mm2 6. 1103 cm2 7. 50.27 m2
9
2
4. } 5. }
7
64
Lesson 11.6
Standardized Test A, Chapter 11
Practice A
1. 308 2. 22.58 3. 98 4. B 5. C 6. D 7. A
1. B 2. C 3. C 4. C 5. C 6. B 7. B
8. 6.1 in. 9. 8.3 ft 10. 64 square units
8. B 9. A 10. C 11. B 12. C 13. A
11. about 41.6 square units
12. about 187.1 square units
13. about 152.8 square units 14. 277.0 m2
14. C 15. B 16. 150 17. a. 600 ft2
b. No; it will be 22, or 4, times greater than the current
area. 18. a. 37.7 in. b. 113.1 in.2 c. 12.6 in.
d. 75.4 in.2
15. 906.9 cm2 16. 24 units; 41.6 square units
17. 45.3 units; 128 square units
Lesson 12.1
18. 72.7 units; 363.3 square units
Practice A
19. false 20. true 21. a. 458
2
b. 15 in.; about 16.2 in.; about 745.6 in.
A26
Geometry
IDEA! Works
1. no; Solid has a curved surface. so it is not a
polyhedron 2. yes; trapezoidal prism faces: 6,
vertices: 8, edges: 12 3. no; Solid has a curved
surface; so it is not a polyhedron. 4. 6 5. 9
6. 12
Copyright © Holt McDougal Math. All rights reserved.
2