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

% Ex. No. 72 (Section  8.10.1 : Example with \tkzcname{tkzAutoLabelPoints})

\begin{tikzpicture}[scale=1.25]
  \tkzDefPoint(2,1){O}
  \tkzDefRandPointOn[circle=center O radius 1.5cm]
  \tkzGetPoint{A}
  \tkzDrawCircle(O,A)
  \tkzDefPointBy[rotation=center O angle 100](A)
  \tkzGetPoint{C}
  \tkzDefPointBy[rotation=center O angle 78](A)
  \tkzGetPoint{B}
  \tkzDrawPoints(O,A,B,C)
  \tkzDrawSegments(C,B B,A A,O O,C)
  \tkzDefCentroid(A,B,C,O)
  \tkzDrawPoint(tkzPointResult)
  \tkzAutoLabelPoints[center=tkzPointResult,
                     dist=.3,red](O,A,B,C)
\end{tikzpicture}

\end{document}