the base of the "square" pyramid is an 11x11 square, and its height is 12, therefore
[tex]\bf \textit{volume of a pyramid}\\\\
V=\cfrac{1}{3}Bh\quad
\begin{cases}
B=\textit{area of its base}\\
h=height\\
---------\\
B=\stackrel{11\times 11}{121}\\
h=12
\end{cases}\implies V=\cfrac{(121)(12)}{3}[/tex]