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

% Ex. No. 97 (Section 14.1.2 : Example of extending an segment with option \tkzname{add})

\begin{tikzpicture}
  \tkzDefPoints{0/0/A,6/0/B,0.8/4/C}
  \tkzDefTriangleCenter[euler](A,B,C)
  \tkzGetPoint{E}
  \tkzDrawCircle[euler,red](A,B,C)
  \tkzDrawLines[add=.5 and .5](A,B A,C B,C)
  \tkzDrawPoints(A,B,C,E)
  \tkzLabelPoints(A,B,C,E)
\end{tikzpicture}

\end{document}