# Worksheet: Circumference of a Circle

In this worksheet, we will practice finding the circumference of a circle using the formula 2πr.

Q1:

Work out the circumference of the circle given that , giving your answer accurate to two decimal places.

Q2:

Work out the circumference of the circle, giving your answer accurate to two decimal places.

Q3:

Using 3.14 to approximate , what is the diameter of a circle of circumference 125.6 cm?

Q4:

Using 3.14 to approximate and the fact that is a square, calculate the perimeter of the shaded part.

Q5:

The circumference of a circle is a function of its diameter represented by the equation . If the diameter is the input and the circumference is the output, calculate the circumference when the diameter is 5.

• A
• B
• C

Q6:

If the radius of a circle equals 13.8 cm, find the length of its longest chord.

Q7:

Find the circumference of a circle whose radius is 12.4 cm. Give your answer to the nearest centimeter.

Q8:

Using to approximate , what is the difference in circumference between a circle of radius 77 cm and one of radius 63 cm?

Q9:

Using to approximate , what is the difference in circumference between a circle of diameter 63 cm and one of diameter 49 cm?

Q10:

Using 3.14 to approximate , what is the difference in circumference between a circle of diameter 100 cm and one of radius 15 cm?

Q11:

Work out the circumference of the circle, giving your answer accurate to two decimal places.

Q12:

Work out the circumference of the circle, giving your answer accurate to two decimal places.

Q13:

Work out the circumference of the circle, giving your answer accurate to two decimal places.

Q14:

The two circles shown in the diagram are concentric. Work out the circumference of the larger circle, giving your answer in terms of .

• A
• B
• C
• D
• E

Q15:

What is the radius of a circle with circumference cm?

Q16:

Using 3.14 to approximate , determine the number of turns that a wheel of diameter 55 cm makes in rolling a distance of 345.4 cm.

Q17:

Determine the perimeter of the figure, using 3.14 to approximate .

Q18:

Use 3.14 to approximate and calculate the circumference of the circle.

Q19:

What is the formula for the circumference of a circle with radius ?

• A
• B
• C
• D

Q20:

Work out the circumference of a circle with a diameter of 10 inches, giving your answer to two decimal places.

Q21:

The formula for the circumference of a circle is . Find the circumference of a circle with a diameter of 12 in. Give your answer in terms of , knowing that the diameter is equal to .

• A in
• B in
• C in
• D in

Q22:

Find, to the nearest hundredth, the circumference of a circle of diameter 55.5 cm.

Q23:

The length of the longest chord in a circle is 40.3 cm. Find its circumference. You may approximate by 3.14.

Q24:

Using 3.14 to approximate , what is the circumference of a circle of diameter 34 cm?

Q25:

Using to approximate , what is the circumference of a circle where half of the diameter is 56 cm?