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

% Ex. No. 38 (Section  6.1.3 : Option \tkzname{circum})

\begin{tikzpicture}
  \tkzDefPoints{0/1/A,3/2/B,1/4/C}
  \tkzDefTriangleCenter[circum](A,B,C)
  \tkzGetPoint{G}
  \tkzDrawPolygon[color=brown](A,B,C)
  \tkzDrawCircle(G,A)
  \tkzDrawPoints(A,B,C,G)
\end{tikzpicture}

\end{document}