The circumference of a circle is 8 cm. Find the area of the sector whose central angle is 72°.
Given:
Circumference of circle = 8 cm
Central angle = 72°
∵ Circumference of a circle = 2πr
∴ 2πr = 8
2 × × r = 8
r = 8 × ×
r = cm
∵ Area of sector = × πr2
=
= 1.02 cm2