There are two formulae for this:
angle/360 X (pi) X (radius squared) = Area of a sector
angle/360 X (pi) X (diameter) = Arc Length of sector
or
angle/360 X (2) X (pi) X (radius) = Arc Length of sector
If you want to work out the perimeter of a sector, use this formula:
Arc Length + (2 X radius) = Perimeter of sector.
