Sector area

Two separate the area of a circle into two sectors - the major sector and the minor sector.

To calculate the sector area, first find what fraction of the whole circle we have.

Calculate the area of this sector which has a 60° angle to one decimal place.

60° is one sixth of a full turn (360°).

The sector is \(\frac{1}{6}\) of the full area.

Remember the area of a circle = \(\pi r^2\)

The sector area is: \(\frac{1}{6} \times \pi \times 4^2 = 8.4~\text{cm}^2\)

The formula to calculate the sector area is: \(\text{Sector area} = \frac{\text{angle}}{360} \times \pi \times r^2 \)

Question

Calculate the minor sector area to one decimal place.

Calculate the major sector area to one decimal place.