\input{preamble-standalone.ltx} \begin{document} % Ex. No. 147 (Section 18.1.8 : Spieker circle with option \tkzname{spieker}) \begin{tikzpicture}[scale=1] \tkzDefPoints{ 0/0/A,4/0/B,0.8/4/C} \tkzDefSpcTriangle[medial](A,B,C){M_a,M_b,M_c} \tkzDefTriangleCenter[spieker](A,B,C) \tkzGetPoint{S_p} \tkzDrawPolygon[blue](A,B,C) \tkzDrawPolygon[red](M_a,M_b,M_c) \tkzDrawPoints[blue](B,C,A) \tkzDrawPoints[red](M_a,M_b,M_c,S_p) \tkzDrawCircle[in,red](M_a,M_b,M_c) \tkzAutoLabelPoints[center=S_p,dist=.3](M_a,M_b,M_c) \tkzLabelPoints[blue,right](S_p) \tkzAutoLabelPoints[center=S_p](A,B,C) \end{tikzpicture} \end{document}