Given that area of circle is 64cm we can assume we will need to first find radius and then calculate circumference.
First we know that area of a circle is [tex]A=\pi r^2[/tex] hence [tex]r=\sqrt{\dfrac{A}{\pi}}[/tex]
We can now put in our area,
[tex]r=\sqrt{\dfrac{64}{\pi}}\approx20.37[/tex]
Then we use the formula for circumference,
[tex]C=2\pi r\Longrightarrow C=2\pi\cdot20.37\approx\boxed{128\mathbf{cm}}[/tex]
Hope this helps.
r3t40
