Answer:
[tex]18\pi m[/tex]
Step-by-step explanation:
to find the circumference we need to find the radius of the circle.
For this, we use the formula for the area :
[tex]a=\pi r^2[/tex]
where [tex]a[/tex] is the area, [tex]\pi[/tex] is a constant [tex]\pi =3.1416[/tex] and [tex]r[/tex] is the radius.
we know that the area is:
[tex]a=81\pi m^2[/tex]
so we substitue this into the previous formula:
[tex]81\pi m^2=\pi r^2[/tex]
and we solve for [tex]r[/tex] :
[tex]\frac{81\pi m^2}{\pi }=r^2\\ \\81m^2=r^2\\\\\sqrt{81m^2}=r\\\\9m=r[/tex]
the radius is 9 meters.
Now we use the formula for circumference of a circle:
[tex]C=2 \pi r[/tex]
and substitute the value that we've just found for r:
[tex]C=2\pi (9m)\\C=18\pi m[/tex]
the answer in terms of [tex]\pi[/tex] is [tex]18\pi[/tex] meters is the circumference
