### Overlapping Circles

What shaped overlaps can you make with two circles which are the same size? What shapes are 'left over'? What shapes can you make when the circles are different sizes?

### Pi, a Very Special Number

Read all about the number pi and the mathematicians who have tried to find out its value as accurately as possible.

### Circles, Circles Everywhere

This article for pupils gives some examples of how circles have featured in people's lives for centuries.

# Yin Yang

##### Stage: 2 Challenge Level:

Many thanks to Alistair of Histon Junior School, who sent in this solution:

Set compass to 3 cm.
Mark a point in pencil and draw a circle around that point with the compass.
Draw a vertical line with a ruler through the middle of the circle.
Measure and mark each 1.5 cm along it.
Set compass to 1.5 cm.
Draw semicircle to the left around the lowest 1.5cm mark.
Draw another semicircle to the right around the topmost 1.5cm mark.
Set compass to a very small size, and draw circles around both 1.5cm marks.
Rub out vertical line and centre marks.