SOLUTION: the diameter of the circleis 5 cm. the angle of the unshaded portion is 60 degrees. find the area of the unshaded potion.

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Question 75497: the diameter of the circleis 5 cm. the angle of the unshaded portion is 60 degrees. find the area of the unshaded potion.
Answer by ptaylor(2198) About Me  (Show Source):
You can put this solution on YOUR website!

The area(A) of a circle is:
A=pi%2Ar%5E2
In this problem, r=d%2F2=5%2F2=2.5cm. Plug this in for r:
A=pi%2A%282.5%29%5E2
A=6.25%2Api
Since a circle has 360 degrees,the shaded portion represents 60/360 or 1/6 of the circle. So the area of the shaded portion is 1/6 of the total area or:
Area of shaded portion:
As=%281%2F6%29%286.25%2Api%29

As=1.041%2Api and that's about equal to pi

Hope this helps---ptaylor