\[\boxed{\mathbf{519.}ОК\ ГДЗ\ –\ домашка\ на\ 5}\]
\[Дано:\]
\[Найти:\]
\[Решение.\]
\[1)\ Длины\ сторон\ \]
\[параллелепипеда\ \]
\[(по\ теореме\ Пифагора):\]
\[a^{2} + c^{2} = 81;\ \ \ \ \ c^{2} + b^{2} = 49;\ \ \ \ \]
\[a^{2} + b^{2} = 64;\]
\[c^{2} - b^{2} = 17;\ \ \ \ \ \ \ \ c^{2} + b^{2} = 49;\]
\[2c^{2} = 66\ \]
\[c^{2} = 33\]
\[c = \sqrt{33}.\]
\[b^{2} = 49 - c^{2} = 49 - 33 = 16\]
\[b = 4.\]
\[a^{2} = 81 - c^{2} = 81 - 33 = 48\]
\[a = 4\sqrt{3}.\]
\[2)\ V = abc = 4\sqrt{3} \bullet 4 \bullet \sqrt{33} =\]
\[= 16 \bullet \sqrt{99} = 48\sqrt{11}\ см^{3}.\]
\[Ответ:\ \ V = 48\sqrt{11}\ см^{3}.\]