\input{preamble-standalone.ltx} \begin{document} % Ex. No. 164 (Section 22.4.3 : Mélange de styles) \begin{tikzpicture}[scale=.75] \tkzDefPoint(0,0){A} \tkzDefPoint(4,1){B} \tkzDefPoint(2,5){C} \tkzDefPointBy[projection=onto B--A](C) \tkzGetPoint{H} \tkzDrawLine(A,B) \tkzDrawLine[add = .5 and .2,color=red](C,H) \tkzMarkRightAngle[,size=1,color=red](C,H,A) \tkzMarkRightAngle[german,size=.8,color=blue](B,H,C) \tkzFillAngle[opacity=.2,fill=blue!20,size=.8](B,H,C) \tkzLabelPoints(A,B,C,H) \tkzDrawPoints(A,B,C) \end{tikzpicture} \end{document}