YOU ARE LEARNING:
We can divide circles up into sectors, and find out information about them using some of the formulae we have learned.
As well as knowing how to calculate the circumference and area of a circle, it is useful to working out proportions of these quantities; arcs and sectors.
The angle of a sector is 108°. If the radius is 5, what is the length of the arc?
We can use the same logic to find the area of a sector, as a sector is just a proportion of the total circle area.