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

% Ex. No. 60 (Section 10.1.1 : Option \tkzname{colinear at})

\begin{tikzpicture}[scale=1.2,
   vect/.style={->,shorten >=3pt,>=latex'}]
  \tkzDefPoint(2,3){A}   \tkzDefPoint(4,2){B}
  \tkzDefPoint(0,1){C}
  \tkzDefPointWith[colinear=at C](A,B)
  \tkzGetPoint{D}
  \tkzDrawPoints[color=red](A,B,C,D)
  \tkzLabelPoints[above right=3pt](A,B,C,D)
  \tkzDrawSegments[vect](A,B C,D)
\end{tikzpicture}

\end{document}