documentclass{article}
usepackage{tikz}
usepackage{pgf}
usepackage{pgfplots}
usetikzlibrary{arrows}
begin{document}
begin{tikzpicture}
  draw [line width=1pt] (0,0)-- (5,0);
  draw [line width=1pt] (5,0)-- (5,5);
  draw [line width=1pt] (5,5)-- (0,5);
  draw [line width=1pt] (0,5)-- (0,0);
  draw [fill=black] (0,0) circle (1.8pt);
  draw[color=black] (0.05,-0.45) node {$D$};
  draw [fill=black] (5,0) circle (1.8pt);
  draw[color=black] (5.05,-0.45) node {$C$};
  draw [fill=black] (5,5) circle (1.8pt);
  draw[color=black] (5.0,5.4) node {$B$};
  draw [fill=black] (0,5) circle (1.8pt);
  draw[color=black] (0.05,5.4) node {$A$};
  draw[color=black] (2.5,-0.45) node {$e_3$};
  draw[color=black] (5.4,2.7) node {$e_2$};
  draw[color=black] (2.5,5.3) node {$e_1$};
  draw[color=black] (-0.4,2.7) node {$e_4$};
 end{tikzpicture}

end{document}