Answer Key

Answer Key

Chapter 9 – Distance and Area 9.1

Evaluation of Square Roots

Answers 1. 4



2. 5



3. 1



4. 7



5. 12

6. 9



7. 13



8. 11



9. 10



10. 16

11. 3 and 4

12. 3 and 4

13. 5 and 6

14. 6 and 7

15. 7 and 8

16. 8 and 9

17. 8 and 9

18. 10 and 11 19. 2 and 3

20. 3 and 4

9.2

Evaluation of Perfect Square Roots

Answers 1. 6

2. 7

3. 8

4. 9

5. 10

6. 11

7. 12

8. 14

9. 20

10. 30

11. 100

12. 15

13. 16

14. 18

15. square roots are each a whole number

9.3

Simplification of Radical Expressions

Answers 1. 18



2. 25



3. 26



4. 120

5. 9

6. 35



7. 21



8. 24



9. 21



10. 23

11. 3



12. 47

13. 31

14. 9



15. 25

9.4

Equations with Square Roots

Answers 1. 3



2. 7



3. 10



4. 8



5. 15

6. 16



7. 3



8. 5



9. 6



10. 8

11. 9



12. 99

13. 6



14. 2



15. 3





CK-12 Middle School Math Concepts - Grade 7

1

Answer Key

Chapter 9 – Distance and Area 9.5

Estimation of Square Roots

Answers 1. 2.8

2. 3.3

3. 4.9

4. 5.6

5. 6.1

6. 6.6

7. 7.7

8. 8.2

9. 8.5

10. 8.9

11. 9.7

12. 9.9

13. 10

14. 12.2

15. 11.7

9.6

Properties of Rational versus Irrational Numbers

Answers 1. Irrational

2. Rational

3. Rational

4. Rational

5. Irrational

6. Rational

7. Rational

8. Irrational

9. Irrational

10. Rational

11. Irrational

12. Rational

13. Irrational

14. Rational

15. Irrational

9.7

Pythagorean Theorem and Its Converse

Answers 1. 10



2. 15

6. 40



7. 8.6

8. 14.2

9. 15.6

10. 14. 4

12. 12.04

13. 16.55

14. 14.31

15. 14.42

11. 13.6

9.8



3. 20



4. 25



5. 30

Solving Equations Using the Pythagorean Theorem

Answers 1. 10.4



2. 12

3. 3





4. 15.6

5. 20





6. 6.6

7. 8.7



8. 7.5

9. 1.52 + 22 = c2

10. 2.5 m tall

11. 32 + 42 = c2

12. 5 miles

13. 5.52 + b2 = 14.52

14. 13.4 inches





CK-12 Middle School Math Concepts - Grade 7

2

Answer Key

Chapter 9 – Distance and Area 9.9

Area of a Parallelogram

Answers 1. 45 sq. in.





3. 72 sq. ft.

4. 88 sq. meters

5. 130 sq. yds.



6. 10 sq. ft.

7. 19.25 sq. in

8. 58.5 sq. ft.



9. 396 sq. miles

10. 348 sq. meters

11. 242 square meters

12. 585 sq. meters

13. 1000 sq. meters

14. 4,400 sq. meters

15. 1106 sq. meters

9.10



2. 12 sq. in.





Unknown Dimensions of Parallelograms

Answers 1. 5 ft

2. 2.5 in.

3. 9 ft

4. 10 in.

5. 2.5 ft.

6. 12 in.

7. 18 ft.

8. 16 m

9. 2 in.

10. 5 miles

11. 6 in.

12. 2 meters

13. 15 ft.

14. 11 ft.

15. 11 ft.

16. 8 miles

17. 3 meters

18. 4 feet

9.11

Estimation of Parallelogram Area in Scale Drawings

Answers 1. 96 sq. ft.



2. 192 sq. ft.





3. 64 sq. ft.

4. 80 sq. ft.



5. 144 sq. ft.





6. 320 sq. ft.

7. 528 sq. ft.



8. 540 sq. ft.





9. 720 sq. ft.

10. 26 cm



11. 42 in.





12. 398.94 sq. cm



15. 223 cm

13. 2210 sq. ft.

9.12

14. Kara’s, 3.3 inches

Triangle Area

Answers 1. 18 in2

2. 9 in2



3. 14 in2



4. 31.5 m2



5. 60 ft2

6. 35 ft2

7. 91 ft2



8. 44 m2



9. 55.25 ft2



10. 51.75 m2

11. 135 m2

12. 162.75 ft2

13. 99 ft2



14. 158.88 m2



15. 440 ft2



CK-12 Middle School Math Concepts - Grade 7

3

Answer Key

Chapter 9 – Distance and Area 9.13

Unknown Dimensions of Triangles

Answers 1. 3 m

2. 6 m

3. 3 m

4. 6 ft

5. 5 ft

6. 12 ft

7. 9 in

8. 18 in

9. 9 ft.

10. 6 in.

11. 10 in

12. 14 ft.

13. 18 in

14. 17 ft.

15. 13 in.

9.14

Area of Composite Shapes Involving Triangles

Answers 1. 66.5 sq. in.

2. 99 sq. in.



3. 126 sq. in.

4. 45 sq. ft.



5. 45 sq. ft



6. 120 sq. ft.

7. 102 sq. ft.



8. 150 sq. in.



9. 132.5 sq. in

10. 220.25 sq. in.

11. 82.5 sq. in

12. 24 cm

13. 13 in.

14. 432 sq. ft.

15. 16.5 sq. in.

9.15



Circle Circumference

Answers 1. 12.56 in.

2. 12.56 in.

3. 28.26 in.

4. 25.12 m

5. 75.36 in.

6. 37.68 mm

7. 87.92 mm

8. 40.82 ft.

9. 62.8 in

10. 23.55 ft.

11. 15.7 in

12. 35.17 ft.

13. 11.78 ft.

14. 14.13 ft.

15. 33.76 m

9.16

Diameter or Radius of a Circle Given Circumference

Answers 1. 5 ft

2. 6.5 in.

3. 7 m

4. 1.5 cm

5. 15 ft.

6. 7 in.

7. 2.5 m

8. 2.25 in.

9. 3.25 cm

10. 2 ft.

11. 102.05 m

12. 420.76 cm

13. 45.40 ft.

14. 55 inches

15. 100 cm

16. 6.5 ft.

17. 3548.2 m

18. 138.16 in.





CK-12 Middle School Math Concepts - Grade 7

4

Answer Key

Chapter 9 – Distance and Area 9.17

Area of a Circle

Answers 1. 28.26 sq. in

2. 78.5 sq. in



3. 50.24 sq. ft.

4. 153.86 sq. m

5. 113.04 sq. cm

6. 38.47 sq. in

7. 200.96 sq. in

8. 153.86 sq. cm

9. 314 sq. in

10. 176.63 sq. m

11. 379.94 sq. cm

12. 452.16 sq. mm

13. 1808.64 sq. in.

14. 854.87 sq. in

15. 2082.02 sq. in

9.18

Radius or Diameter of a Circle Given Area

Answers 1. 2 in

2. 5 m

3. 8 cm

4. 9 in

5. 1.5 ft.

6. 3 m

7. 4 in

8. 10 m

9. 16 cm

10. 18 in

11. 3 ft

12. 6 m

13. 28 ft.

14. 15 m

15. 12 ft

9.19

Areas of Combined Figures Involving Circles

Answers 1. 168.49 sq. mm

2. 100.61 sq. in.

3. 73.19 sq. in.

4. 235.33 sq. ft.

5. 334.55 sq. ft.

6. 49.81 sq. ft.

7. 65.13 sq. ft.

8. 72.29 sq. in.

9. 47.23 sq. ft.

10. 24.06 sq. ft.

11. 19.81 sq. in

12. 40.23 sq. in.

13. 22.87 sq. in

14. 452.16 sq. ft.

15. 138,474 sq. ft.



CK-12 Middle School Math Concepts - Grade 7

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