SOLUTION: How do I get the surface area of a sphere with C=7π cm? Thanks!

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Question 1142671: How do I get the surface area of a sphere with C=7π cm? Thanks!
Found 2 solutions by josgarithmetic, josmiceli:
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
If r is radius, S is surface area, and C is Circumference, then you should already know these formulas:

system%28C=2pi%2Ar%2CS=4pi%2Ar%5E2%29

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STEPS

2pi%2Ar=7pi
r=7%2F2
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S=4pi%2A%287%2F2%29%5E2
S=4pi%2A49%2F4
highlight%28S=49pi%29

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+C+=+2pi%2Ar+
+C+=+7pi+
+2pi%2Ar+=+7pi+
+2r+=+7+
+r+=+7%2F2+
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+A+=+4pi%2Ar%5E2+
+A+=+4pi%2A%287%2F2%29%5E2+
+A+=+49pi+
get a 2nd opinion if needed