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

% Ex. No. 73 (Section  8.10.2 : 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)
 \tkzAutoLabelPoints[center=O,red](A,B,C)
\end{tikzpicture}

\end{document}