In order to derive the formula to calculate the angle at the centre of the sector, the formulae for the arc length and area of a sector can be rearranged so that we can calculate the fraction of ...

Calculate the arc length to 2 decimal places. First calculate what fraction of a full turn the angle is ... d\) and the diameter = \(2 \times \text{radius}\). The arc length is \(\frac{1}{ ...