\input{preamble-standalone.ltx} \begin{document} % Ex. No. 211 (Section 25.4.1 : Example) \begin{tikzpicture}[scale=.5] \tkzDefPoint(0,0){A} \tkzDefPoint(3,-4){B} \tkzDefCircle[through](A,B) \tkzGetLength{rABpt} \tkzpttocm(\rABpt){rABcm} \tkzDrawCircle(A,B) \tkzDrawPoints(A,B) \tkzLabelPoints(A,B) \tkzDrawSegment[dashed](A,B) \tkzLabelSegment(A,B){$\pgfmathprintnumber{\rABcm}$} \end{tikzpicture} \end{document}