\input{preamble-standalone.ltx} \begin{document} % Ex. No. 35 (Section 5.3 : Internal Similitude Center) \begin{tikzpicture}[scale=.75,rotate=-30] \tkzDefPoint(0,0){O} \tkzDefPoint(4,-5){A} \tkzDefIntSimilitudeCenter(O,3)(A,1) \tkzGetPoint{I} \tkzExtSimilitudeCenter(O,3)(A,1) \tkzGetPoint{J} \tkzDefTangent[from with R= I](O,3 cm) \tkzGetPoints{D}{E} \tkzDefTangent[from with R= I](A,1 cm) \tkzGetPoints{D'}{E'} \tkzDefTangent[from with R= J](O,3 cm) \tkzGetPoints{F}{G} \tkzDefTangent[from with R= J](A,1 cm) \tkzGetPoints{F'}{G'} \tkzDrawCircle[R,fill=red!50,opacity=.3](O,3 cm) \tkzDrawCircle[R,fill=blue!50,opacity=.3](A,1 cm) \tkzDrawSegments[add = .5 and .5,color=red](D,D' E,E') \tkzDrawSegments[add= 0 and 0.25,color=blue](J,F J,G) \tkzDrawPoints(O,A,I,J,D,E,F,G,D',E',F',G') \tkzLabelPoints[font=\scriptsize](O,A,I,J,D,E,F,G,D',E',F',G') \end{tikzpicture} \end{document}