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
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