Respuesta :
[tex]\bf \textit{volume of a cylinder}\\\\
V=\pi r^2 h\qquad
\begin{cases}
r=radius\\
h=height\\
-----\\
V=315\pi \\
h=21
\end{cases}\implies 315\pi =\pi r^2(21)
\\\\\\
\cfrac{315\pi }{21\pi }=r^2\implies 15=r^2\implies \boxed{\sqrt{15}=r}\\\\
-------------------------------\\\\
\textit{since the area of the base of the cylinder is a circle with radius \underline{r}}
\\\\\\
\textit{area of a circle}\\\\
A=\pi r^2\qquad A=\pi \left( \boxed{\sqrt{15}} \right)^2\implies A=15\pi [/tex]
Answer:
its B=36
Step-by-step explanation:
i toke the test and ur welcome
