\documentclass{standalone}
\usepackage{tikz}


\begin{document}
\begin{tikzpicture}[scale=.9]

\fill[lime] (-6,0)--(0,4)--(6,0)--(3,-2)--(-3,-2);

\node at (-3,2.4) {\rotatebox{33}{$x=3t/2-3$}};
\node at (-4.5,-1.3) {\rotatebox{-33}{$x=-3t/2-3$}};


\node at (3,2.5) {\rotatebox{-33}{$x=3t/2+3$}};
\node at (4.5,-1.3) {\rotatebox{33}{$x=-3t/2+3$}};

\node[below] at (0,-2) {$t=-1$};

\draw[thin,->] (-6.1,0)--(6.3,0) node[above]{$x$};
\draw[thin,->] (0,-2.5)--(0,4.2) node[above]{$t$};

\end{tikzpicture}
\end{document}