Watch: Parts of a circle
All circles have a circumference, diameter and radius. They can be measured using a ruler or tape measure.
- The circumference is the distance all the way around a circle.
- The diameter is the distance right across the middle of the circle.
- The radius is the distance halfway across the circle. The radius is always half the length of the diameter.
Time for a much needed makeover. I have always thought you were a bit on the scruffy side.
Hmm, not convinced these are the best guys for the job though.
But, no no no. Give it a go.
First, you'll need to measure the radius. That鈥檚 the measurement from the centre of the circle to the edge.
From the radius you can work out the diameter. That's the distance right across the centre of the circle.
The diameter is always twice as long as the radius.
And now the circumference. That's the distance all the way around the side of the circle.
Right, looking forward to seeing this.
Yeah鈥ouldn't give up the day job.
Activity
NEW! Play Guardians: Defenders of Mathematica - the Halloween update. game
Experience Mathematica as you鈥檝e never seen it before, with all-new backgrounds and costumes for Halloween. Available for a limited time only. Use your maths skills to save the day before it's too late!
More on 2d shapes
Find out more by working through a topic
- count4 of 10
- count5 of 10
- count6 of 10
- count7 of 10
