1. Circle – Circumference & Perimeter – Worksheet A
The worksheet is provided in four differently-structured formats.
Students can use the ‘Circles To Measure’ sheet,
or they can measure circular – or more difficult - spherical objects:
food packaging; toilet rolls, bottles, batteries, tins, cans, cups, mugs…

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’.

4. Circumference Investigation START START START START START ① Object 1
1) Pick a circular object.
Circumference
Investigation
2) From START, mark 3 diameters next to each other on the line.
3) Using a tape measure, measure the circumference of the object. Or roll the object along the line once.
4) Mark the circumference on the line.
5) What conclusions can you make about relationship between the circumference and the diameter of a circle?
START
Object 1
START
Object 2
START
Object 3
START
Object 4
START
Object 5

5. Circumference = 3….. × Diameter What is the relationship
between a circle’s
circumference and its diameter?
Circumference = … × Diameter
Circumference = 𝜋 × Diameter
𝜋 (Pi) is the relationship between
a circle’s diameter and its circumference.
Circumference
Preview the slide show to check the animations.
Diameter 1
Diameter 2
Diameter 3
3.14

6. Circumference = 𝜋 × Diameter
𝜋 (Pi) is the relationship between
a circle’s diameter and its circumference.
Circumference
Diameter 1
Diameter 2
Diameter 3
3.14

7. How circular is your head?
Plenary
How circular is your head?
Get your partner to measure the
circumference & the diameter (length).
Divide the circumference by the diameter.
The closer you are to 3.14,
the closer it is to a circle!

8. Circumference Investigation START START START START START ① Object 1
1) Pick a circular object.
Circumference
Investigation
2) From START, mark 3 diameters next to each other on the line.
3) Using a tape measure, measure the circumference of the object. Or roll the object along the line once.
4) Mark the circumference on the line.
5) What conclusions can you make about relationship between the circumference and the diameter of a circle?
START
Object 1
START
Object 2
START
Object 3
START
Object 4
START
Object 5

9. Circumference Investigation START START START START START START ②
1) Pick a circular object.
2) From START, mark 3 diameters next to each other on the line.
3) Using a tape measure, measure the circumference of the object. Or roll the object along the line once.
4) Mark the circumference on the line.
5) What conclusions can you make about relationship between the circumference and the diameter of a circle?
START
Object 1
START
Object 2
START
Object 3
START
Object 4
START
Object 5
START
Object 6

10. ③ ③ Circumference Investigation Circumference Investigation c ÷ d
1) Pick a circular object.
1) Pick a circular object.
2) Measure the diameter (d).
2) Measure the diameter (d).
3) Measure the circumference (c).
3) Measure the circumference (c).
4) How many diameters go into the circumference?
4) How many diameters go into the circumference?
5) What conclusion can you make from your investigation?
5) What conclusion can you make from your investigation?
Circular Object
Diameter
(d)
Circumference
(c)
How many diameters in a circumference?
c ÷ d
Circular Object
Diameter
(d)
Circumference
(c)
How many diameters in a circumference?
c ÷ d

11. START START START START START START START ④ Object 1 Object 2 Object 3

12. Circles To
Measure

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