\input{preamble-standalone.ltx} \begin{document} % Ex. No. 91 (Section 13.1.3 : Example with the option \tkzname{add}) \begin{tikzpicture}[scale=.5] \tkzDefPoint(0,0){O} \tkzDefPoint(3,1){I} \tkzDefPoint(1,4){J} \tkzDefLine[bisector](I,O,J) \tkzGetPoint{i} \tkzDefLine[bisector out](I,O,J) \tkzGetPoint{j} \tkzDrawLines[add = 1 and .5,color=red](O,I O,J) \tkzDrawLines[add = 1 and .5,color=blue](O,i O,j) \end{tikzpicture} \end{document}