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

% Ex. No. 48 (Section  8.1.1 : Use of option \tkzname{pos})

\begin{tikzpicture}
  \tkzDefPoints{0/0/A,4/0/B}
  \tkzDrawLine[red](A,B)
  \tkzDefPointOnLine[pos=1.2](A,B)
  \tkzGetPoint{P}
  \tkzDefPointOnLine[pos=-0.2](A,B)
  \tkzGetPoint{R}
  \tkzDefPointOnLine[pos=0.5](A,B)
  \tkzGetPoint{S}
  \tkzDrawPoints(A,B,P)
  \tkzLabelPoints(A,B)
  \tkzLabelPoint[above](P){pos=$1.2$}
  \tkzLabelPoint[above](R){pos=$-.2$}
  \tkzLabelPoint[above](S){pos=$.5$}
  \tkzDrawPoints(A,B,P,R,S)
  \tkzLabelPoints(A,B)
\end{tikzpicture}

\end{document}