<PRE><B>Question 1115207</B>
 Find the radius of a circle which has a sector area of 9 pi whose central angle is 90 degrees. 
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A 90 deg sector has 1/4 the  area of the circle.
Total circle area = 4*9pi = 36pi
Equation:
pi*r^2 = 36pi
radius = 6
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Cheers,
Stan H.
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