\input{preamble-standalone.ltx} \begin{document} % Ex. No. 53 (Section 9.2.3 : Example of projection) \begin{tikzpicture}[scale=1.5] \tkzDefPoint(0,0){A} \tkzDefPoint(0,4){B} \tkzDefTriangle[pythagore](B,A) \tkzGetPoint{C} \tkzDefLine[bisector](B,C,A) \tkzGetPoint{c} \tkzInterLL(C,c)(A,B) \tkzGetPoint{D} \tkzDefPointBy[projection=onto B--C](D) \tkzGetPoint{G} \tkzInterLC(C,D)(D,A) \tkzGetPoints{E}{F} \tkzDrawPolygon[teal](A,B,C) \tkzDrawSegment(C,D) \tkzDrawCircle(D,A) \tkzDrawSegment[orange](D,G) \tkzMarkRightAngle[fill=orange!20](D,G,B) \tkzDrawPoints(A,C,F) \tkzLabelPoints(A,C,F) \tkzDrawPoints(B,D,E,G) \tkzLabelPoints[above right](B,D,E,G) \end{tikzpicture} \end{document}