Read all about the number pi and the mathematicians who have tried to find out its value as accurately as possible.
This article for pupils gives some examples of how circles have featured in people's lives for centuries.
Can you reproduce the Yin Yang symbol using a pair of compasses?
Can you describe the sides of the shapes you can make?
Do you notice anything about all the shapes you make using two circles the same size?
When the two circles are different sizes, what else is possible?