Form 2 KSSM Circles

What is A?

Calculate the circumference of a circle with a diameter of 2m. Use

 $\pi=3.142$  . Write your answer in 2 decimal places.

Calculate the circumference of a circle with a radius of 12cm. Use

 $\pi=\frac{22}{7}$  . Write your answe in 2 decimal places.

The formulae

 $2\pi r$  . What does r represent?

Find a diameter of a circle with circumference 36cm. Use

 $\pi=3.142$  . Write your answer in 2 decimal places.

Find a radius of a circumference of 63.5mm. Use

 $\pi=\frac{22}{7}.$  Write your answer in 2 decimal places.

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

Is C the diameter of the circle?

• Yes

• No

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

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. Use π = 3.142. Write your answer in 2 decimal places.