Question

Can somebody help me with these to questions how do you find the area of the circle

Answer 1

13)

Circumference (C) = 2π·r

11π = 2π·r

11/2 = r

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Area (A) = π·r²

             =  π·(11/2)²  

            = 121π/4

           ≈ 94.985 in²

14)

diameter = 2r

          42 = 2r

           21 = r

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Area (A) = π·r²

             =  π·(21)²  

            = 441π

           ≈ 1384.74 in²

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$280/1384.74 in²

x = $0.20

Answer: about 20 cents per square inch