Math CentralQuandaries & Queries


Question from Mel:

Find the area of a sector of a circle that has a central angle of 13pi/18 and a radius of 12cm. Round answer to nearest 10th degree

Hi Mel,

If the sector were the entire circle the central angle would be 2 π radians and the area would be π r2 = π 122 cm2. Your sector has a central angle which is only a fraction of the central angle of the entire circle, in fact the fraction is (13π/18)/(2π). By the symmetry of the circle the area of your sector is the same fraction of the area of the circle.

I hope this helps,

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