\begin{tikzpicture}
	\begin{axis}[
		axis on top,
		axis lines=center,
		xlabel={$x$},
		ylabel={$y$},
		zlabel={$z$},
		xlabel style={below right},
		ylabel style={above left},
		yticklabel style={left},
		view={20}{20},
		xmin=-1,
		xmax=15,
		ymin=0,
		zmin=0,
		zmax=8,
		xtick={0,2, 8,10},
		xticklabels={$0$, $\xrx$, $\xtx$, $B$},
		ytick={0,40},
		yticklabels={$0$, $\yrx$},
		ztick={0,5},
		zticklabels={$0$, $H$},
		]
		\addplot3[mark=,fill=black!10,opacity=.3] coordinates {(0, 0, 0) (0, 0, 5) (0, 50, 5) (0, 50, 0) (0, 0, 0)};
		
		\addplot3[mark=,fill=black!10,opacity=.3] coordinates {(10, 0, 0) (10, 0, 5) (10, 50, 5) (10, 50, 0) (10, 0, 0)};
		
		\addplot3[mark=,fill=black!10,opacity=.3] coordinates {(0, 0, 5) (10, 0, 5) (10, 50, 5) (0, 50, 5) (0, 0, 5)};
		
		\coordinate (tx) at (8, 0, 2);
		\draw[-<,thick] (8, 0, 0) -- node[left] {$\htx$} (tx);
		
		\coordinate (rx) at (2, 40, 1);
		\draw[-<,thick] (2, 40, 0) -- node[right] {$\hrx$} (rx);
		\draw[dashed,gray] (0, 40, 0) -- (2, 40, 0);
		\draw[dashed,gray] (2, 40, 0) -- (2, 0, 0);
	\end{axis}
\end{tikzpicture}