## Circles Exercise

1. Name the parts of the circle, shown by letters.

Use π = 3.14 for all of the following questions up to question 10, and give your answers correct to 3 significant figures.

2. A circle has a radius of 12 cm. What is its circumference?

3. A cirlce has a diameter of 24.8 mm. What is its circumference?

4. Find the circumference and the area of the following circles:

 a. b. c.

5. Find the perimeter and area of the following shapes:

 a. b. c.

6. Find the radius of a circle given that its circumference is 3.9 cm.

7. Find the diameter of a circle given that its circumference is 83 metres.

8. Find radius of a circle given that its area is 34.9 mm2

9. A car tyre has an outside diameter of 85 cm, what is its circumference?

 10 A wheel is used to measure the length of a running race. Every time it does one revolution it is recorded on a counter. If the wheel has a diameter of 25 cm and it turns 15345 revolutions when measuring the course, how far, to the nearest metre, is the race?