SOLUTION: Dimensions of a Quarter. The circumference of a quarter is 7.85cm. What is the diameter? Radius? The area? I have done this problme over and over again, but still come up with the

Algebra ->  Circles -> SOLUTION: Dimensions of a Quarter. The circumference of a quarter is 7.85cm. What is the diameter? Radius? The area? I have done this problme over and over again, but still come up with the      Log On


   

Question 459840: Dimensions of a Quarter. The circumference of a quarter is 7.85cm. What is the diameter? Radius? The area?
I have done this problme over and over again, but still come up with the wrong answer! What am i doing wrong:
D= 7.85/2=
R= 3.14x7.85=
A=3.14x2.925x2.925
My book gave me the answer but I still can not figure out how to write the problem because my book does not explain how to do this one problem correcty?
Thank you for your help.
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Dimensions of a Quarter. The circumference of a quarter is 7.85cm. What is the diameter? Radius? The area?
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Circumference = (pi)d
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7.85 = (pi)d
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Diameter = 7.85/3.14 = 2.5 cm.
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Radius + (1/2)(2.5) = 1.25 cm
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Area = (pi)r^2 3.14*1.25^2 = 4.91 sq cm
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Cheers,
Stan H.
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