平行四边形TikZ作图

 %!TEX program = pdflatex
documentclass[varwidth=true, border=2pt]{standalone}

usepackage{tikz}
usepackage{mathpazo}

usetikzlibrary{arrows}
usetikzlibrary{decorations.markings}

egin{document}
egin{tikzpicture}[x=.5cm,y=.5cm]
draw [<->,>=stealth'] (0,8) node [label = left:{$y$}]{} -- (0,0) -- (12,0) node[label = below:{$x$}]{};
    grid[xstep=.5cm, ystep=.5cm] (4,4);
    draw (0,0) -- (5*1.414,0) -- (5+5*1.414,5) -- (5,5) -- cycle;
    draw[fill=green!10] (0,0) -- (5*1.414,0) -- (5+5*1.414,5) -- (5,5) -- cycle;
    draw (0,0)node[label = below:{$(0,0)$}]{};
    draw (5*1.414,0)node[label = below:{$(sqrt{2},0)$}]{};
    draw (5+5*1.414,5)node[label = above:{$(sqrt{2}+1,1)$}]{};
    draw (5,5)node[label = above:{$(1,1)$}]{};
  end{tikzpicture}
end{document}