Form 2 Chapter 5: Circles

What is A?

Calculate the circumference of a circle with a diameter of 2 m. Write your answer in 2 decimal places. (Use  $\pi=3.142$ ) 

Calculate the circumference of a circle with a radius of 12 cm. Write your answer in 2 decimal places. (Use

 $\pi=\frac{22}{7}$ )

The formulae

 $2\pi r$ .

What does $r$ represent?

Find a diameter of a circle with circumference 36 cm. Write your answer in 2 decimal places. (Use  $\pi=3.142$ )

Find a radius of a circumference of 63.5 mm. Write your answer in 2 decimal places. (Use  $\pi=\frac{22}{7}$ )

A round-shape cake has a circumference of 54 cm. What is the radius of the cake? Write your answer in 2 decimal places. (Use  $\pi=3.142$ )

Is C the diameter of the circle?

• Yes

• No

Calculate the arc length of the sector given in the picture. Write your answer in 3 decimal places. (Use $\pi=3.142$ )

A ball fits exactly into a square box as shown in the diagram. If the length of the box is 21cm, find the circumference of the circle. Write your answer in 2 decimal places. (Use  $\pi=3.142$ )