SOLUTION: I tried subtracting 12 from 100 and then using the formula for the area of a circle solve it but I couldn't find the answer so I'm not sure what I was supposed to do or if I was do

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Question 1073045: I tried subtracting 12 from 100 and then using the formula for the area of a circle solve it but I couldn't find the answer so I'm not sure what I was supposed to do or if I was doing it wrong.
Question: The figure below shows a circular garden surrounded by a circular drive. The outside circle of the drive has a diameter of 100 meters and the drive has a uniform width of 12 meters. Which of the following is closest to the area, in square meters, of the garden?
A. 240
B. 310
C. 4500
D. 7900
E. 18000

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
The figure below shows a circular garden surrounded by a circular drive. The outside circle of the drive has a diameter of 100 meters and the drive has a uniform width of 12 meters. Which of the following is closest to the area, in square meters, of the garden?
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Subtract 12 from the radius, not from the diameter.
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Inside area = pi*r^2
r = 50-12 = 38 m
Area = 1444pi = 4536 sq meters.
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