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

% Ex. No. 164 (Section 20.2.6 : Calculation of radius example 2)

\begin{tikzpicture}
  \tkzDefPoint(2,2){A}
  \tkzDefPoint(5,4){B}
  \tkzDefPoint(4,4){O}
  \edef\tkzLen{\fpeval{0.0002/0.0001}}
  \tkzDrawCircle[R](O,\tkzLen cm)
  \tkzInterLC[R](A,B)(O, \tkzLen cm)
  \tkzGetPoints{I}{J}
  \tkzDrawPoints[color=blue](A,B)
  \tkzDrawPoints[color=red](I,J)
  \tkzDrawLine(I,J)
\end{tikzpicture}

\end{document}