\input{preamble-standalone.ltx} \begin{document} % Ex. No. 40 (Section 6.1.5 : Option \tkzname{ex}) \begin{tikzpicture}[scale=.5] \tkzDefPoints{0/1/A,3/2/B,1/4/C} \tkzDefTriangleCenter[ex](B,C,A) \tkzGetPoint{J_c} \tkzDefPointBy[projection=onto A--B](J_c) \tkzGetPoint{Tc} %or % \tkzDefCircle[ex](B,C,A) % \tkzGetFirstPoint{J_c} % \tkzGetSecondPoint{Tc} \tkzDrawPolygon[color=blue](A,B,C) \tkzDrawPoints(A,B,C,J_c) \tkzDrawCircle[red](J_c,Tc) \tkzDrawLines[add=1.5 and 0](A,C B,C) \tkzLabelPoints(J_c) \end{tikzpicture} \end{document}