The circumference of a circle = \(\pi d\) or \(2\pi r\). Look at the sector of the circle shown below. To calculate the length of the arc, we need to know what fraction of the circle is shown. To do ...

Imagine a circle. Does it have a colour? Does it have a centre? Make your circle get bigger and bigger. Use your arms to show me how big your circle is. Now make your circle get as small as possible.