Perimeter, area and volume · Ages 11–12

Circumference and area together worksheet

Part of: Circumference and area of a circle

In the print window, choose “Save as PDF” to download it. The answers print on the last page.

Perimeter, area and volume · Ages 11–12

Numsprite
numsprite.com

Name:Date:Score:／48

Write each answer in the space. For word problems, show your working and write a sentence answer.

13.A circular rug has a radius of 3 m. What is its area, in square metres? (Take π as 3.14.)
Answer as a decimal
Working:
Answer:
14.A circular flower bed has a diameter of 4 m. What is its circumference, in metres? (Take π as 3.14.)
Answer as a decimal
Working:
Answer:
15.A semicircular flower bed has a diameter of 20 m. How many metres of fencing are needed to go all the way round it, straight side included? (Take π as 3.14.)
Answer as a decimal
Working:
Answer:
16.A bicycle wheel has a diameter of 60 cm. It turns 23 times. How many centimetres does the bicycle travel? (Take π as 3.14.)
Answer as a decimal
Working:
Answer:
17.A semicircular flower bed has a diameter of 14 m. How many metres of fencing are needed to go all the way round it, straight side included? (Take π as 3.14.)
Answer as a decimal
Working:
Answer:
18.A bicycle wheel has a diameter of 70 cm. It turns 6 times. How many centimetres does the bicycle travel? (Take π as 3.14.)
Answer as a decimal
Working:
Answer:

Show the answers and working

Circumference and area together worksheet: Answers and working

1. Perimeter of the semicircle = 41.12 cm
A semicircle's perimeter is half the circumference + the diameter: 3.14 × 16 = 50.24, 50.24 ÷ 2 = 25.12, 25.12 + 16 = 41.12, so 41.12
2. Diameter = 20 cm
Diameter = circumference ÷ 3.14: 62.8 ÷ 3.14 = 20, so 20
3. Area of the circle = 200.96 cm²
A circle's area = 3.14 × radius × radius: the radius is the diameter ÷ 2, 16 ÷ 2 = 8, 8 × 8 = 64, 3.14 × 64 = 200.96, so 200.96
4. Diameter = 18 cm
Diameter = circumference ÷ 3.14: 56.52 ÷ 3.14 = 18, so 18
5. Circumference = 15.7 cm
Circumference = 3.14 × diameter: 3.14 × 5 = 15.7, so 15.7
6. Circumference = 56.52 cm
Circumference = 3.14 × diameter: 3.14 × 18 = 56.52, so 56.52
7. Perimeter of the semicircle = 5.14 cm
A semicircle's perimeter is half the circumference + the diameter: 3.14 × 2 = 6.28, 6.28 ÷ 2 = 3.14, 3.14 + 2 = 5.14, so 5.14
8. Area of the semicircle = 157 cm²
A semicircle's area is half the circle's: 10 × 10 = 100, 3.14 × 100 = 314, 314 ÷ 2 = 157, so 157
9. Area of the circle = 153.86 cm²
A circle's area = 3.14 × radius × radius: 7 × 7 = 49, 3.14 × 49 = 153.86, so 153.86
10. Area of the semicircle = 14.13 cm²
A semicircle's area is half the circle's: 3 × 3 = 9, 3.14 × 9 = 28.26, 28.26 ÷ 2 = 14.13, so 14.13
11. Circumference = 31.4 cm
Circumference = 3.14 × diameter: 3.14 × 10 = 31.4, so 31.4
12. Area of the semicircle = 1.57 cm²
A semicircle's area is half the circle's: 1 × 1 = 1, 3.14 × 1 = 3.14, 3.14 ÷ 2 = 1.57, so 1.57

Marking: 2 for the working, 1 for the answer, 1 for the sentence.

13. A circular rug has a radius of 3 m. What is its area, in square metres? (Take π as 3.14.) (Answer: 28.26 m²)
3.14 × 3 × 3 = 28.26
14. A circular flower bed has a diameter of 4 m. What is its circumference, in metres? (Take π as 3.14.) (Answer: 12.56 m)
3.14 × 4 = 12.56
15. A semicircular flower bed has a diameter of 20 m. How many metres of fencing are needed to go all the way round it, straight side included? (Take π as 3.14.) (Answer: 51.4 m)
3.14 × 20 ÷ 2 = 31.4; 31.4 + 20 = 51.4
16. A bicycle wheel has a diameter of 60 cm. It turns 23 times. How many centimetres does the bicycle travel? (Take π as 3.14.) (Answer: 4333.2 cm)
3.14 × 60 = 188.4; 3.14 × 60 × 23 = 4333.2
17. A semicircular flower bed has a diameter of 14 m. How many metres of fencing are needed to go all the way round it, straight side included? (Take π as 3.14.) (Answer: 35.98 m)
3.14 × 14 ÷ 2 = 21.98; 21.98 + 14 = 35.98
18. A bicycle wheel has a diameter of 70 cm. It turns 6 times. How many centimetres does the bicycle travel? (Take π as 3.14.) (Answer: 1318.8 cm)
3.14 × 70 = 219.8; 3.14 × 70 × 6 = 1318.8

Numsprite · numsprite.com/en/worksheets/circumference-and-area-of-a-circle/circumference-and-area-together