\input{preamble-standalone.ltx} \begin{document} % Ex. No. 165 (Section 20.2.7 : Calculation of radius example 3) \begin{tikzpicture} \tkzDefPoints{2/2/A,5/4/B,4/4/0} \tkzLength=2cm \tkzDrawCircle[R](O,\tkzLength) \tkzInterLC[R](A,B)(O,\tkzLength) \tkzGetPoints{I}{J} \tkzDrawPoints[color=blue](A,B) \tkzDrawPoints[color=red](I,J) \tkzDrawLine(I,J) \end{tikzpicture} \end{document}