Thank you.
Code: Select all
\documentclass{article}
\begin{document}
% a square with labeled vertices
\setlength{\unitlength}{3cm}
\begin{picture}(2,2)
\linethickness{0.3mm}
\put(0,0){\line(1,0){1}}
\put(0,0){\circle*{.05}}
\put(1,0){\circle*{.05}}
\put(1,1){\circle*{.05}}
\put(0,1){\circle*{.05}}
\put(0,0){\line(0,1){1}}
\put(1,0){\line(0,1){1}}
\put(0,1){\line(1,0){1}}
\put(-0.1,1.05){$1$}
\put(1,1.05){$2$}
\put(1.05,-0.05){$3$}
\put(-0.13,-0.05){$4$}
\end{picture}
\end{document}