If the area of a circle is 8pi what is the length of its diameter?

A = pi r^(2)

and 2r = d

Substituting

8pi = pi r^(2)

Cancel down by 'pi'

8 = r^(2) r = 2sqrt(2)

So 2r = d = 2(2sqrt(2) = 4sqrt(2). The answer !!!!

Numerically 4sqrt(2) = 5.656.... units of length .