Circle Parts and Circumference
Part A: Identifying Circle Parts
Label the following parts of the circle below:
1. The centre (black dot): ______________________
2. The blue line from centre to edge: ______________________
3. The red line across the whole circle: ______________________
4. The distance around the circle: ______________________
Part B: Circumference Formula
Circumference = π × diameter
C = πd or C = 2πr
(Use π = 3.14 unless otherwise stated)
Part C: Calculate the Circumference
Show your working. Round answers to 1 decimal place.
5. A circle has a diameter of 10 cm. Find the circumference.
Working: _________________________________________
Circumference = _____________ cm
6. A circle has a diameter of 15 m. Find the circumference.
Working: _________________________________________
Circumference = _____________ m
7. A circle has a radius of 7 cm. Find the circumference.
Working: _________________________________________
Circumference = _____________ cm
8. A circle has a radius of 12 m. Find the circumference.
Working: _________________________________________
Circumference = _____________ m
9. A bicycle wheel has a diameter of 65 cm. How far does the bicycle travel in one complete rotation of the wheel?
Working: _________________________________________
Distance = _____________ cm
10. A circular garden has a radius of 4.5 m. What length of edging is needed to go around the entire garden?
Working: _________________________________________
Length of edging = _____________ m