Math 7-4.2 Multiple Choice Identify the choice that best completes the statement or answers the question. 1. Find the circumference of this circle. Leave π in your answer. 12 m A) m B) m C) m D) 12 m 2. Find the circumference of this circle. Leave π in your answer. 34 cm A) cm B) cm. C) cm D) cm 3. Find the circumference of this circle. Leave π in your answer. 8.8 cm A) cm B) cm C) cm D) cm 4. Estimate the circumference of this circle.
29 m A) 174 m B) 32 m C) 44 m D) 87 m 5. Estimate the circumference of this circle. 12 cm A) 18 cm B) 36 cm C) 15 cm D) 108 cm 6. Estimate the diameter of a circle with circumference 57 m. A) 9.5 m B) 28.5 m C) 19 m D) 38 m 7. The circumference of a circle is cm. Find the diameter and radius. A) 68 cm; 17 cm B) 17 cm; 34 cm C) 34 cm; 68 cm D) 34 cm; 17 cm 8. The radius of a circular lid is 3.1 cm. Calculate the circumference. Round your answer to one decimal place. A) 4.9 cm B) 6.2 cm C) 9.7 cm D) 19.5 cm 9. The circumference of a circle is 21 cm. Calculate the radius. Round your answer to one decimal place. A) 6.7 cm B) 10.5 cm C) 3.6 cm
D) 3.3 cm 10. Calculate the circumference of this circle. Round your answer to two decimal places. 7.4 m A) 46.50 m B) 22.20 m C) 23.25 m D) 172.03 m 11. Calculate the circumference of this circle. Round your answer to one decimal place. 14.2 cm A) 7.1 cm B) 22.3 cm C) 42.6 cm D) 44.6 cm 12. Find the diameter of a circle with a circumference of 14.3 mm. Round your answer to one decimal place. A) 7.2 mm B) 2.3 mm C) 4.6 mm D) 9.1 mm 13. Calculate the circumference of this circle. Round your answer to one decimal place. 8 m A) 50.3 m B) 201.1 m C) 100.5 m D) 25.1 m
14. The distance around Earth at the equator is about 40 074 km. Find the diameter at the equator of Earth. Round your answer to the nearest kilometre. A) 25 512 km B) 12 756 km C) 62 884 km D) 6 339 700 km 15. A circle has a circumference of 32.4 mm. Find the radius and the diameter. Round your answers to two decimal places. A) 5.16 mm; 10.31 mm B) 10.31 mm; 5.16 mm C) 5.16 mm; 2.58 mm D) 2.58 mm; 5.16 mm 16. Calculate the circumference of this circle. Round your answer to one decimal place. 10.8 cm A) 91.6 cm B) 33.9 cm C) 67.9 cm D) 17.0 cm Short Answer 17. A circular lawn has a diameter of 22 m. The lawn is surrounded by a path 5 m wide. What is the distance around the outside edge of the path? Round your answer to two decimal places.. 18. The circumference of a circular pond is 78.5 m.
What is the diameter of the pond? Round your answer to the nearest metre.. 19. A round table has a circumference of 4.3 m. What is the radius to the nearest centimetre? 20. The dotted circle is midway between the two circles. The outer circle has a circumference of 9.42 cm. The inner circle has a circumference of 28.27 cm. What is the radius of the dotted circle?. 21. A circular garden has radius 2.2 m. The garden is to be surrounded by edging wire. Edging wire is sold in whole metre lengths. a) How many metres of wire are needed?
b) Edging wire costs $4.63/m. What is the cost to edge the garden? 22. A bicycle wheel has a radius of 32 cm. How far will the bicycle travel if the wheel makes 500 rotations?. 23. What is the perimeter of the semicircle? Round your answer to two decimal places. 12 cm Problem 24. The 2 sides of this running track are in the shape of semicircles. Find the distance around the track. Round your answer to the nearest metre. Show your work.
55 m 100 m 25. The diameter of a tire is 0.75 m. a) Find the circumference of the tire. Round your answer to two decimal places. b) About how many times will the tire have to rotate to travel 1 km? 26. A metal gate is made of a square frame of side length 68 cm and 4 circles. What is the total length of metal required to make the frame and the 4 circles? Round your answer to the nearest centimetre. Show your work. 68 cm 27. This spiral consists of 3 semicircles with centres at A, B, and C. If the length of AB is 5.0 cm, what is the length of the spiral? Round the answer to one decimal place. Show your work.
D B C A E. 28. Find the perimeter of the figure. Round your answer to one decimal place. 24 cm 12 cm. 29. Which has the greater circumference: the large circle or the sum of the four smaller circles? Explain.
44 cm
Math 7-4.2 Answer Section MULTIPLE CHOICE 1. ANS: A PTS: 1 DIF: Easy REF: 4.2 Circumference of a Circle LOC: 7.SS1 TOP: Shape and Space (Measurement) KEY: Conceptual Understanding 2. ANS: A PTS: 1 DIF: Easy REF: 4.2 Circumference of a Circle LOC: 7.SS1 TOP: Shape and Space (Measurement) KEY: Conceptual Understanding 3. ANS: A PTS: 1 DIF: Easy REF: 4.2 Circumference of a Circle LOC: 7.SS1 TOP: Shape and Space (Measurement) KEY: Conceptual Understanding 4. ANS: A PTS: 1 DIF: Easy REF: 4.2 Circumference of a Circle 5. ANS: B PTS: 1 DIF: Easy REF: 4.2 Circumference of a Circle 6. ANS: C PTS: 1 DIF: Easy REF: 4.2 Circumference of a Circle 7. ANS: D PTS: 1 DIF: Moderate REF: 4.2 Circumference of a Circle 8. ANS: D PTS: 1 DIF: Moderate REF: 4.2 Circumference of a Circle 9. ANS: D PTS: 1 DIF: Moderate REF: 4.2 Circumference of a Circle 10. ANS: A PTS: 1 DIF: Moderate REF: 4.2 Circumference of a Circle 11. ANS: D PTS: 1 DIF: Moderate REF: 4.2 Circumference of a Circle 12. ANS: C PTS: 1 DIF: Moderate REF: 4.2 Circumference of a Circle 13. ANS: A PTS: 1 DIF: Moderate REF: 4.2 Circumference of a Circle 14. ANS: B PTS: 1 DIF: Moderate REF: 4.2 Circumference of a Circle 15. ANS: A PTS: 1 DIF: Moderate REF: 4.2 Circumference of a Circle 16. ANS: B PTS: 1 DIF: Moderate REF: 4.2 Circumference of a Circle SHORT ANSWER 17. ANS: d = 22 + 5 2 = 32 The diameter of the large circle, including the lawn and path, is 32 m. C = 100.53 The distance around the outside edge of the path is 100.53 m.
18. ANS: d = 78.5 25 The diameter of the pond is about 25 m. PTS: 1 DIF: Moderate REF: 4.2 Circumference of a Circle 19. ANS: r = 4.3 (2 π) 0.7 The radius is about 0.7 m or 70 cm. PTS: 1 DIF: Moderate REF: 4.2 Circumference of a Circle 20. ANS: 3 cm 21. ANS: a) 14 m b) $64.82 22. ANS: C = 201 Distance = 201 500 = 100531 The distance travelled is about 100531 cm or 1005.31 m. 23. ANS: 30.85 cm PROBLEM 24. ANS: Methods may vary. Sample: Curved distance: Total distance: The distance around the track is about 373 m.
25. ANS: a) b) The circumference of the tire is about 2.36 m. The tire has to rotate about 424 times to travel 1 km. 26. ANS: Methods may vary. Sample: Length of square frame: Radius of each circle: Circumference of 4 circles: Total length of metal: 699 cm of metal is required. 27. ANS: Methods may vary. Sample: Semicircle on AB: Semicircle on AD: Semicircle on DE: Length of spiral: The length of the spiral is about 55 cm. 28. ANS: Semicircle: 37.7 P = 37.7 + 12 + 24 + 12 = 85.7 The perimeter is about 85.7 cm.
29. ANS: Large circle: d = 22 C = π 22 69.12 Small circle: d = 11 C = 4 π 11 138.23 The four smaller circles have the greater circumference.