Ans: B
Let $h\text{ cm}$ be the height of the circular cone. Since the volumes of two solid are the same, we have
Let $h\text{ cm}$ be the height of the circular cone. Since the volumes of two solid are the same, we have
$\begin{array}{rcl}
\pi (3)^2 \times 12 & = & \dfrac{1}{3} \times \pi (6)^2 \times h \\
108 & = & 12 h \\
h & = & 9
\end{array}$
Therefore, the height of the circular cone is $9\text{ cm}$.
