Question

what is the circumference of a round pizza with an area of 36 square inches?

Answer 1

Knowing that your area is: $A= \pi r^{2}=36 in^{2}$ you can find the radius as:
$r= \sqrt{ \frac{36}{ \pi } } =3.4 in$;
With this you can evaluate the circumference as:
$C=2 \pi r=2*3.14*3.4=21.3 in$