Arturo O. answered • 06/23/17
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A = πr2 [area]
Get radius r from the circumference C.
C = 2πr [circumference]
r = C/(2π)
Then
A = πr2 = π [C/(2π)]2
Now just plug in the given circumference C of 28 cm and get area A in cm2. Can you finish from here?
Arturo O.
A = πr2 = π[C/(2π)]2 = C2/(4π) ≅ 62.39 cm2
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06/23/17
Arturo O.
A = (28 cm)2 / (4π) ≅ 62.39 cm2
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06/23/17
Nancy C.
I guess I'm confused because you are not using 3.14
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06/23/17
Arturo O.
Do you see how we get to
A = C2/(4π) ?
Now plug in the numbers. You can round off π to 3.14 if you wish.
A = (28 cm)2 / [4(3.14)] ≅ 62.4 cm2 [rounded off]
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06/23/17
Nancy C.
I see now. thanks for your time.
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06/23/17
Arturo O.
You are welcome, Nancy.
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06/23/17
Nancy C.
06/23/17