 # Find Areas of Circles Using Their Diameters

In this worksheet, students work out the areas of circles given their diameters. Key stage:  KS 3

Curriculum topic:   Geometry and Measures

Curriculum subtopic:   Solve Problems Involving Perimeters and Areas of 2D Shapes

Difficulty level:   ### QUESTION 1 of 10

This worksheet is about finding the areas of circles, given their diameters.

You must learn this important formula for a circle of radius, r :

Area of a circle = π r2

Remember that the radius is HALF the diameter.

Example

Find the area of a circle of diameter 12 cm.

First work out the radius, which will be 12 ÷ 2 = 6 cm

Area = π r2 =  π x 62 = π x 36 = 113.1 cm2  (1 dp)

Find the area of a circle of diameter 20cm in cm2.

(Just write the number to 1 decimal place)

Find the area of a circle of diameter 2cm in cm2.

(Just write the number to 1 decimal place)

Find the area of a circle of diameter 10cm in cm2.

(Just write the number to 1 decimal place)

Find the area of a circle of diameter 6cm in cm2.

(Just write the number to 1 decimal place)

Find the area of a circle of diameter 16cm in cm2.

(Just write the number to 1 decimal place)

Find the area of a circle of diameter 25cm in cm2.

(Just write the number to 1 decimal place)

Find the area of a circle of diamter 5.8cm in cm2.

(Just write the number to 1 decimal place)

Find the area of a circle of diameter 22.4cm in cm2.

(Just write the number to 1 decimal place)

Find the area of a circle of diameter 0.5cm in cm2.

(Just write the number to 1 decimal place)

Find the area of a circle of diameter 6.9cm in cm2.

(Just write the number to 1 decimal place)

• Question 1

Find the area of a circle of diameter 20cm in cm2.

(Just write the number to 1 decimal place)

314.2
EDDIE SAYS
The diamater is 20 so the radius is 10 A = π x 102
• Question 2

Find the area of a circle of diameter 2cm in cm2.

(Just write the number to 1 decimal place)

3.1
EDDIE SAYS
The diamater is 2 so the radius is 1 A = π x 12
• Question 3

Find the area of a circle of diameter 10cm in cm2.

(Just write the number to 1 decimal place)

78.5
EDDIE SAYS
The diamater is 10 so the radius is 5 A = π x 52
• Question 4

Find the area of a circle of diameter 6cm in cm2.

(Just write the number to 1 decimal place)

28.3
EDDIE SAYS
The diamater is 6 so the radius is 3 A = π x 32
• Question 5

Find the area of a circle of diameter 16cm in cm2.

(Just write the number to 1 decimal place)

201.1
EDDIE SAYS
The diamater is 16 so the radius is 8 A = π x 82
• Question 6

Find the area of a circle of diameter 25cm in cm2.

(Just write the number to 1 decimal place)

490.9
EDDIE SAYS
The diamater is 25 so the radius is 12.5 A = π x 12.52
• Question 7

Find the area of a circle of diamter 5.8cm in cm2.

(Just write the number to 1 decimal place)

26.4
EDDIE SAYS
The diamater is 5.8 so the radius is 2.9 A = π x 2.92
• Question 8

Find the area of a circle of diameter 22.4cm in cm2.

(Just write the number to 1 decimal place)

394.1
EDDIE SAYS
The diamater is 22.4 so the radius is 11.2 A = π x 11.22
• Question 9

Find the area of a circle of diameter 0.5cm in cm2.

(Just write the number to 1 decimal place)

0.2
EDDIE SAYS
The diamater is 0.5 so the radius is 0.25 A = π x 0.252
• Question 10

Find the area of a circle of diameter 6.9cm in cm2.

(Just write the number to 1 decimal place)

37.4
EDDIE SAYS
The diamater is 6.9 so the radius is 3.45 A = π x 3.452
---- OR ----

Sign up for a £1 trial so you can track and measure your child's progress on this activity.

### What is EdPlace?

We're your National Curriculum aligned online education content provider helping each child succeed in English, maths and science from year 1 to GCSE. With an EdPlace account you’ll be able to track and measure progress, helping each child achieve their best. We build confidence and attainment by personalising each child’s learning at a level that suits them.

Get started 