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?
What shaped overlaps can you make with two same-sized circles?
What shapes are 'left over'?
What shapes can you make when the circles are different sizes?
What happens when you use more than two circles?