Question

The area of a circle is 16pi cm2. What is the circle's circumstance?

Answer 1

I think you mean circumference...Area is $A= \pi r^{2}$. We have the area so we need to use it to solve for the radius which we will then use in the circumference formula.  $16 \pi = \pi r^{2}$.  Divide both sides by pi to get $\frac{16 \pi }{ \pi } = r^{2}$.  Of course the simplification of the left side gives us $16= r^{2}$ and r = 4.  Now fill that in to the circumference formula, which is $C=2 \pi r$, to get C$C=2 \pi (4)$ which is a circumference of $8 \pi$