\[h = 7\ дм.\ \]
\[b = h - 1 = 7 - 1 = 6\ (дм) -\]
\[ширирна.\]
\[a = 2b = 2 \cdot 6 = 12\ (дм) -\]
\[длина.\]
\[V = abh = 7 \cdot 6 \cdot 12 = 42 \cdot 12 =\]
\[= 504\ дм^{3}.\]
\[Ответ:504\ дм^{3}.\]