\input{preamble-standalone.ltx} \begin{document} % Ex. No. 41 (Section 9.2.1 : Example of homothety and projection) \begin{tikzpicture}[scale=1.25] \tkzInit \tkzClip \tkzDefPoint(0,1){A} \tkzDefPoint(6,3){B} \tkzDefPoint(3,6){C} \tkzDrawLines[add= 0 and .3](A,B A,C) \tkzDefLine[bisector](B,A,C) \tkzGetPoint{a} \tkzDrawLine[add=0 and 0,color=magenta!50 ](A,a) \tkzDefPointBy[homothety=center A ratio .5](a) \tkzGetPoint{a'} \tkzDefPointBy[projection = onto A--B](a') \tkzGetPoint{k} \tkzDrawSegment[blue](a',k) \tkzDrawPoints(a,a',k,A) \tkzDrawCircle(a',k) \tkzLabelPoints(a,a',k,A) \end{tikzpicture} \end{document}