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}

\begin{document}
\begin{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}