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

% Ex. No. 49 (Section  8.2 : Point on a circle)

\begin{tikzpicture}
 \tkzDefPoints{0/0/A,4/0/B,0.8/3/C}
 \tkzDefPointOnCircle[angle=90,center=B,radius=1 cm]
 \tkzGetPoint{I}
 \tkzDefCircle[circum](A,B,C)
 \tkzGetPoint{G} \tkzGetLength{rG}
 \tkzDefPointOnCircle[angle=30,center=G,radius=\rG pt]
 \tkzGetPoint{J}
 \tkzDrawCircle[R,teal](B,1cm)
 \tkzDrawPoint[teal](I)
 \tkzDrawPoints(A,B,C)
 \tkzDrawCircle(G,J)
 \tkzDrawPoints(G,J)
 \tkzDrawPoint[red](J)
 \tkzLabelPoints(G,J)
\end{tikzpicture}

\end{document}