\input{preamble-standalone.ltx}
\begin{document}

% Ex. No. 95 (Section 13.3.1 : Vertical line )

\begin{tikzpicture}[scale=2]
   \tkzInit[xmax=3,ymax=1]
   \tkzAxeXY
   \tkzVLine[color      = blue,
             style      = dashed,
             line width = 2pt]{1/3}
\end{tikzpicture}

\end{document}