\documentclass{article} \usepackage[pdftex,active,tightpage]{preview} \setlength\PreviewBorder{2mm} \usepackage{tikz} \usepackage{tkz-euclide} \usetkzobj{all} \usetikzlibrary{shapes, calc, decorations} \usepackage{amsmath,amssymb} \usepackage{helvet} \usepackage[eulergreek]{sansmath} \begin{document} \begin{preview} \begin{tikzpicture}[very thick,font=\sansmath\sffamily] \tkzDefPoint(0,0){A} \tkzDefPoint(3.2,0){B} \tkzDefPoint(4.5,0){Z} \tkzDefPoint(0.7,3){C} \tkzDefBarycentricPoint(A=1,C=2)\tkzGetPoint{X} \tkzInterLL(B,C)(X,Z)\tkzGetPoint{Y} \tkzDefLine[perpendicular=through A,K=1,/tikz/overlay](Y,Z)\tkzGetPoint{YZA} \tkzInterLL(Y,Z)(A,YZA)\tkzGetPoint{YZA} \tkzDefLine[perpendicular=through B,K=1,/tikz/overlay](Y,Z)\tkzGetPoint{YZB} \tkzInterLL(Y,Z)(B,YZB)\tkzGetPoint{YZB} \tkzDefLine[perpendicular=through C,K=1,/tikz/overlay](Y,Z)\tkzGetPoint{YZC} \tkzInterLL(Y,Z)(C,YZC)\tkzGetPoint{YZC} \tkzLabelPoints[below left,font=\sansmath\sffamily](A) \tkzLabelPoints[below right,font=\sansmath\sffamily](B) \tkzLabelPoints[above,font=\sansmath\sffamily](C) \tkzLabelPoints[below left,font=\sansmath\sffamily](X) \tkzLabelPoints[above,font=\sansmath\sffamily](Z) \tkzLabelPoints[above,font=\sansmath\sffamily](Y) % Draw polygon \tkzDrawPolygon[thick,fill=gray!10](A,B,C) % Draw polygon \tkzDrawPolygon[thick](A,B,C) \tkzDrawSegments[thick,color=blue](A,YZA B,YZB C,YZC) \tkzDrawLines[thick](A,Z) \tkzDrawLines[thick,color=red](Z,X) \tkzLabelSegment[right=-0.1,color=blue](A,YZA){a} \tkzLabelSegment[right=-0.01,color=blue](B,YZB){b} \tkzLabelSegment[left=-0.1,color=blue](C,YZC){c} \tkzDrawPoints[color=black,shape=circle,fill=black,size=2](A,B,C,X,Y,Z,YZA,YZB,YZC) \end{tikzpicture} \end{preview} \end{document}