Math 9 · Unit 7: Shapes and measurements · Cambridge Lower Secondary Maths Stage 9

Questions

1. 1. Using π = 3.14, what is the circumference of a circle with diameter 6 cm?

   • 9.42 cm
   • 113.04 cm
   • 18.84 cm
   • 28.26 cm
   Check

2. 2. Using π = 3.14, what is the circumference of a circle with diameter 5 cm?

   • 78.5 cm
   • 15.7 cm
   • 7.85 cm
   • 19.625 cm
   Check

3. 3. Using π = 3.14, what is the circumference of a circle with diameter 9 cm?

   • 63.585 cm
   • 254.34 cm
   • 28.26 cm
   • 14.13 cm
   Check

4. 4. Using π = 3.142, what is the circumference of this circle, to 2 d.p.?

   • 100.54 cm
   • 50.27 cm
   • 25.14 cm
   • 12.57 cm
   Check

5. 5. Using π = 3.142, what is the perimeter of a semicircle with diameter 12 cm, to 2 d.p.?

   • 37.70 cm
   • 56.56 cm
   • 18.85 cm
   • 30.85 cm
   Check

6. 6. Using π = 3.14, what is the area of a circle with radius 4 cm?

   • 12.56 cm²
   • 50.24 cm²
   • 200.96 cm²
   • 25.12 cm²
   Check

7. 7. Using π = 3.14, what is the area of a circle with radius 1 cm?

   • 6.28 cm²
   • 1 cm²
   • 9.86 cm²
   • 3.14 cm²
   Check

8. 8. Using π = 3.14, what is the area of a circle with radius 6 cm?

   • 37.68 cm²
   • 452.16 cm²
   • 18.84 cm²
   • 113.04 cm²
   Check

9. 9. Using π = 3.142, what is the area of a circle with diameter 6 cm, to 2 d.p.?

   • 9.43 cm²
   • 18.85 cm²
   • 113.11 cm²
   • 28.28 cm²
   Check

10. 10. Using π = 3.142, what is the area of this semicircle, to 1 d.p.?

    • 78.6 cm²
    • 39.3 cm²
    • 15.7 cm²
    • 19.6 cm²
    Check

11. 11. What is the area of a circle with radius 2 cm, to 3 s.f.?

    • 6.28 cm²
    • 12.6 cm²
    • 39.5 cm²
    • 12.5 cm²
    Check

12. 12. What is the area of a circle with radius 3.75 m, to 3 s.f.?

    • 44.2 m²
    • 23.6 m²
    • 176 m²
    • 11.8 m²
    Check

13. 13. What is the area of a circle with diameter 28 cm, to 3 s.f.?

    • 88.0 cm²
    • 2460 cm²
    • 616 cm²
    • 176 cm²
    Check

14. 14. What is the area of a circle with diameter 3.2 m, to 3 s.f.?

    • 8.04 m²
    • 5.03 m²
    • 32.2 m²
    • 10.1 m²
    Check

15. 15. Dipti and Gabir work out the area of a circle with diameter 2.4 cm. What mistakes did they make?

    • Both rounded their answers wrongly
    • Both used the diameter instead of the radius
    • Dipti used πd; Gabir used the diameter as the radius
    • Dipti used the diameter as the radius; Gabir used the circumference formula πd
    Check

16. 16. What is the area of a circle with diameter 2.4 cm, to 3 s.f.?

    • 3.77 cm²
    • 7.54 cm²
    • 18.1 cm²
    • 4.52 cm²
    Check

17. 17. A circle has radius 2.7 cm. What are its area and its circumference, to 1 d.p.?

    • area 22.9 cm², circumference 8.5 cm
    • area 22.9 cm², circumference 17.0 cm
    • area 17.0 cm², circumference 22.9 cm
    • area 91.6 cm², circumference 17.0 cm
    Check

18. 18. A circle has diameter 45 mm. What are its area and its circumference, to 1 d.p.?

    • area 6361.7 mm², circumference 141.4 mm
    • area 1590.4 mm², circumference 141.4 mm
    • area 1590.4 mm², circumference 70.7 mm
    • area 141.4 mm², circumference 1590.4 mm
    Check

19. 19. A semicircle has radius 8.5 cm. What are its area and its perimeter, to 1 d.p.?

    • area 113.5 cm², perimeter 43.7 cm
    • area 227.0 cm², perimeter 43.7 cm
    • area 113.5 cm², perimeter 53.4 cm
    • area 113.5 cm², perimeter 26.7 cm
    Check

20. 20. A semicircle has radius 24 mm. What are its area and its perimeter, to 1 d.p.?

    • area 904.8 mm², perimeter 75.4 mm
    • area 904.8 mm², perimeter 198.8 mm
    • area 904.8 mm², perimeter 123.4 mm
    • area 1809.6 mm², perimeter 123.4 mm
    Check