Answer: 8pi
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Step-by-step explanation:
A = 16pi is the area, which means
A = pi*r^2
16pi = pi*r^2
16 = r^2
r^2 = 16
r = sqrt(16)
r = 4
is the radius
Use this to find the circumference C
C = 2*pi*r
C = 2*pi*4
C = 8pi
The exact circumference is 8pi inches long