1. Circle – Area – Worksheet A
Worksheets are more/less structured and in two sizes.

2. Printing To print handouts from slides -
Select the slide from the left. Then click:
File > Print > ‘Print Current Slide’
To print multiple slides -
Click on a section title to highlight all those slides,
or press ‘Ctrl’ at the same time as selecting slides to
highlight more than one. Then click:
File > Print > ‘Print Selection’
To print double-sided handouts -
Highlight both slides before using ‘Print Selection’.
Choose ‘Print on Both Sides’ and ‘Flip on Short Edge’.

3. How can we estimate
the area of the circle?

4. How can we estimate
the area of the circle?
9 units2

5. Area of the square =
4 ×22
2 cm
Area of the circle ≈
3 4 ×4 ×22
3×22

6. Instead of multiplying by 4 to get the area of the square,
4 ×22
2 cm
Area of the circle =
3.14…×22
This is Pi, π
Instead of multiplying by 4 to get the area of the square,
We multiply by …

7. Discovering the Area of a Circle
Part A
1) Estimate the area of the shaded shape.
(Hint: Use rectangles, then estimate the remaining pieces.)
2) Calculate the area of each square.
3) What fraction of the square is shaded? ①
3 4
Your estimate for the shaded fraction ➜
Shaded Area ≈ units2
Square Area = units2
Shaded area as a fraction ≈
16 36
Shaded Area ≈ units2
Square Area = units2
Shaded area as a fraction ≈
78 100
Shaded Area ≈ units2
Square Area = units2
Shaded area as a fraction ≈
Part B
1) Calculate the area of each square.
2) Use your answer from Part A to calculate the area of each circle.
2 cm
5 cm
5 cm
2 cm
3 cm
3 cm
Area = 16 cm2
Area ≈ 12 cm2
Area = 36 cm2
Area ≈ 27 cm2
Area = cm2
Area ≈ 75 cm2
Part C
You now have a formula for the area of a circle! Use the formula to find the area of this circle.
𝑥 cm
𝑥 cm
𝑥 cm
3 4 ×4𝑥2 cm
𝑥 cm
6 cm
Express the area of this square.
Express the area of the circle using the fraction.
Area = 𝑥2
Area = 4𝑥2
Simplify the expression.
Area = 3𝑥2
Area ≈ cm2

8. Discovering the Area of a Circle
Part A ②
What fraction is the area of the circle compared
to the total square?
Shaded Fraction ≈
Shaded Fraction ≈
Shaded Fraction ≈
Part B
Part C
𝑥 cm
With algebra, write an expression for
the area of the square.
Use your fraction from Part A to write an
expression for the area of the circle.
6 cm
Calculate the area of the square.
Use your answer from Part A
to calculate the area of the circle.
𝑆𝑞𝑢𝑎𝑟𝑒= 4𝑥2
Area ≈144 × 3 4
≈108 𝑐𝑚2
𝐶𝑖𝑟𝑐𝑙𝑒≈3𝑥2

9. Discovering the Area of a Circle
Part A
1) Estimate the area of the shaded shape.
(Hint: Use rectangles, then estimate the remaining pieces.)
2) Calculate the area of each square.
3) What fraction of the square is shaded? ①
3 4
Your estimate for the shaded fraction ➜
Shaded Area ≈ units2
Square Area = units2
Shaded area as a fraction ≈
16 36
Shaded Area ≈ units2
Square Area = units2
Shaded area as a fraction ≈
78 100
Shaded Area ≈ units2
Square Area = units2
Shaded area as a fraction ≈
Part B
1) Calculate the area of each square.
2) Use your answer from Part A to calculate the area of each circle.
2 cm
5 cm
5 cm
2 cm
3 cm
3 cm
Area = 16 cm2
Area ≈ 12 cm2
Area = 36 cm2
Area ≈ 27 cm2
Area = cm2
Area ≈ 75 cm2
Part C
You now have a formula for the area of a circle! Use the formula to find the area of this circle.
𝑥 cm
𝑥 cm
𝑥 cm
𝑥 cm
6 cm
Express the area of this square.
Express the area of the circle using the fraction.
Area = 𝑥2
Area = 4𝑥2
Simplify the expression.
Area = 3𝑥2
Area ≈ cm2

11. Discovering the Area of a Circle
Part A ②
What fraction is the area of the circle compared
to the total square?
Shaded Fraction ≈
Shaded Fraction ≈
Shaded Fraction ≈
Part B
Part C
𝑥 cm
With algebra, write an expression for
the area of the square.
Use your fraction from Part A to write an
expression for the area of the circle.
6 cm
Calculate the area of the square.
Use your answer from Part A
to calculate the area of the circle.
Area ≈144 × 3 4
≈108 𝑐𝑚2

13. tom@goteachmaths.co.uk Questions? Comments? Suggestions?
…or have you found a mistake!?
Any feedback would be appreciated .
Please feel free to