Question

Find the circumference of a circle if the area is 300 square centimeters.

Answer 1

$\bf \textit{area of a circle}\\\\ A=\pi r^2~~ \begin{cases} r=radius\\[-0.5em] \hrulefill\\ A=300 \end{cases}\implies 300=\pi r^2\implies \cfrac{300}{\pi }=r^2 \implies \sqrt{\cfrac{300}{\pi }}=\boxed{r}\\\\[-0.35em] \rule{34em}{0.25pt}\\\\ \textit{circumference of a circle}\\\\ C=2\pi r~\hspace{5em}C=2\pi \left( \boxed{\sqrt{\frac{300}{\pi }}}\right)\implies C\approx 61.399602476789$

Answer 2

So the formula for a circle is Pie * r^2

If you divide 300 by pie and then Square root it you would get your radius

And once you have the radius you would use the equation of 2pie * r to find the circumfrence.

Answer is 61.38

Hope this helps!