SOLUTION: find the area of a circle with a circumference of 1/2 inches

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Question 588419: find the area of a circle with a circumference of 1/2 inches
Answer by jim_thompson5910(35256) About Me  (Show Source):
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The formula for circumference is C+=+2pi%2Ar. Use this with C = 1/2 to solve for r:

C+=+2pi%2Ar

1%2F2+=+2pi%2Ar

1%2F4+=+pi%2Ar

1%2F%284pi%29+=+r

r+=+1%2F%284pi%29

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The area of a circle is A+=+pi%2Ar%5E2. Plug in r+=+1%2F%284pi%29 to find the area:

A+=+pi%2Ar%5E2

A+=+pi%2A%281%2F%284pi%29%29%5E2

A+=+pi%2A%281%2F%2816pi%5E2%29%29

A+=+pi%2F%2816pi%5E2%29

A+=+1%2F%2816pi%29


So the exact area of the circle is A+=+1%2F%2816pi%29 square inches.

If you use 3.14 for pi, then the approximate area is 0.019894 square inches.
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