Check the picture below.
so we have a pyramid atop and a rectangular prism at its base, so we simply get the volume of each separately and add them up.
[tex]\hspace{34em}|\\ \textit{volume of a pyramid} \\ \cfrac{1}{3}Bh~~ \begin{cases} B=\stackrel{\textit{area of its base}}{6\times 6}\\ h=\stackrel{\textit{its height}}{8} \end{cases} \\\\\\ \cfrac{1}{3}(6\cdot 6)(8)\implies \cfrac{36}{3}\cdot 8\implies 12\cdot 8\implies \underline{96}[/tex]
[tex]\textit{volume of a rectangular prism}\\ Lwh~~ \begin{cases} L=\stackrel{length}{6}\\ w=\stackrel{width}{6}\\ h=\stackrel{height}{4} \end{cases} \\\\\\ 6\cdot 6\cdot 4\implies 36\cdot 4\implies \underline{144} \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ ~\hfill \stackrel{\textit{volume of the figure}}{96+144\implies 240}~\hfill[/tex]
