\documentclass[varwidth=true, border=2pt]{standalone} \usepackage{tkz-euclide} \usepackage{tikz} \usetikzlibrary{decorations.pathreplacing} \begin{document} \usetkzobj{all} \begin{tikzpicture} \tkzSetUpPoint[shape=circle,size=10,color=black,fill=black] \tkzSetUpLine[line width=1] \tkzDefPoints{0/0/O, 1/0/X, 0/1/Y, 2/1/P, 3/3/Q} \tkzDrawLine[add=3 and 2.2](O,X) \tkzLabelLine[below,pos=3](O,X){$g_1$} \tkzLabelLine[left,pos=3](O,Y){$g_2$} \tkzDrawLine[add=3 and 2.2](O,Y) \tkzDefLine[orthogonal=through P,/tikz/overlay](O,X) \tkzGetPoint{helper} \tkzInterLL(O,X)(P,helper) \tkzGetPoint{xp} \draw [decorate,decoration={brace,amplitude=4pt,mirror}] (O) -- (xp) node [black,midway,xshift=0cm, yshift=-0.3cm] {\footnotesize $x_P$}; \tkzDefLine[orthogonal=through P,/tikz/overlay](O,Y) \tkzGetPoint{helper} \tkzInterLL(O,Y)(P,helper) \tkzGetPoint{yp} \draw [decorate,decoration={brace,amplitude=4pt}] (O) -- (yp) node [black,midway,xshift=-0.4cm] {\footnotesize $y_P$}; \tkzDrawPolygon(O,xp,P,yp) \tkzDefLine[orthogonal=through Q,/tikz/overlay](O,X) \tkzGetPoint{helper} \tkzInterLL(O,X)(Q,helper) \tkzGetPoint{xq} \tkzDefLine[orthogonal=through Q,/tikz/overlay](O,Y) \tkzGetPoint{helper} \tkzInterLL(O,Y)(Q,helper) \tkzGetPoint{yq} \tkzInterLL(yp,P)(Q,xq) \tkzGetPoint{qxp} \tkzInterLL(xp,P)(Q,yq) \tkzGetPoint{R} \tkzDrawPolygon(O,xq,Q,yq) \tkzDrawSegments[green](xp,xq R,Q) \tkzDrawSegments[very thick,orange](yp,yq P,R) \tkzLabelPoint[above right](P){$P$} \tkzLabelPoint[above right](Q){$Q$} \tkzLabelPoint[below left](O){$0$} \tkzLabelPoint[above](R){$R$} \node at ($(-2,2)$){$X$}; \tkzDrawPoints(P,Q,R) \end{tikzpicture} \end{document}