Rounded to 3 significant figures the arc length is 6.28cm. The formula to calculate the arc length is: \(\text{arc length} = \frac{\text{angle}}{360} \times \pi \times d ...

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 ...