Question

Observe the figures below. Radii of all circles are equal. Observe the areas of the shaded regions and complete the following table.

Central angle of a circle = 360°, Area of a circle = πr2
Sector of circle					A
Measure of arc of the sector (θ)
θ/360
Area of the sector

Answer 1

Thus, if measure of an arc of a circle is θ, then Area of sector (A) = θ/360 × Area of circle

∴ Area of sector (A) = θ/360 × πr²