\begin{tikzpicture} \tkzSetUpPoint[shape=circle,size=10,color=black,fill=black] \tkzSetUpLine[line width=1] \tkzDefPoints{0/0/A, 4/0/B, 3/3/C} \tkzDefLine[orthogonal=through A,/tikz/overlay](B,C) \tkzGetPoint{helper} \tkzInterLL(B,C)(A,helper) \tkzGetPoint{La} \tkzDefLine[orthogonal=through C,/tikz/overlay](A,B) \tkzGetPoint{helper} \tkzInterLL(A,B)(C,helper) \tkzGetPoint{Lc} \tkzInterLL(A,La)(C,Lc) \tkzGetPoint{orthocenter} \tkzMarkAngle[arc=l,size=1.0cm,color=red,fill=red!20](B,A,La) \tkzLabelAngle[pos=0.8](B,A,La){$\alpha$} \tkzMarkAngle[arc=l,size=1.0cm,color=red,fill=red!20](Lc,C,B) \tkzLabelAngle[pos=0.8](Lc,C,B){$\alpha$} \tkzMarkAngle[arc=ll,size=0.6cm,color=green,fill=green!20](A,orthocenter,Lc) \tkzLabelAngle[pos=0.4](A,orthocenter,Lc){$\gamma$} \tkzMarkAngle[arc=ll,size=0.4cm,color=green,fill=green!20](La,orthocenter,C) \tkzLabelAngle[pos=0.2](La,orthocenter,C){$\gamma$} \tkzDrawPolygon(A,B,C) \node at ($(A)+(-0.47,-0.2)$){$A$}; \node at ($(B)+(0.35,-0.2)$) {$B$}; % \tkzLabelPoint[below](B){$B$} is not accurate enough \node at ($(C)+(0.05,0.3)$) {$C$}; \node at ($(La)+(0.25,0.1)$) {$L_A$}; \node at ($(Lc)+(0,-0.25)$) {$L_C$}; \tkzDrawSegment(C,Lc) \tkzDrawSegments(A,La) \tkzDrawPolygon[pattern=north east lines](A,B,La) \tkzDrawPolygon[pattern=north west lines](Lc,B,C) \tkzDrawPoints(A,B,C,La,Lc) %\tkzLabelSegment[pos=0.7,below](A,B){$c$} \end{tikzpicture}