\input{preamble-standalone.ltx} \begin{document} % Ex. No. 129 (Section 19.2.2 : Example of tangents passing through an external point ) \begin{tikzpicture}[scale=0.75] \tkzDefPoint(3,3){c} \tkzDefPoint(6,3){a0} \tkzRadius=1 cm \tkzDrawCircle[R](c,\tkzRadius) \foreach \an in {0,10,...,350}{ \tkzDefPointBy[rotation=center c angle \an](a0) \tkzGetPoint{a} \tkzDefTangent[from with R = a](c,\tkzRadius) \tkzGetPoints{e}{f} \tkzDrawLines[color=magenta](a,f a,e) \tkzDrawSegments(c,e c,f) }% \end{tikzpicture} \end{document}