\documentclass[12pt]{standalone}

\usepackage{tikz}

\begin{document}
\begin{tikzpicture}

\draw[thick] (-1,-2) node (A) {} node[below right] {$A$} -- 
    (2,2) node (B) {} node[below right] {$B$};

\draw[thick] (4,3) node (C) {} node[above right] {$C$} -- 
    (5,-3) node (D) {} node[above right] {$D$};

\draw[dashed] (A) rectangle (B)
    (C) rectangle (D);

\fill (A) circle (2pt);
\fill (B) circle (2pt);
\fill (C) circle (2pt);
\fill (D) circle (2pt);

\end{tikzpicture}
\end{document}
