TikZ example

rect.tex

\documentclass[dvipdfmx, tikz, margin = 1pt]{standalone}    
\usepackage{tikz}  
\begin{document}
\begin{tikzpicture}
\tikzset{var/.style = {draw, circle}};
\node[var](A){A};
\node[var, below left of = A](B){B};
\node[var, below right of = A](C){C};
\draw[->] (B)--(A);
\draw[->] (C)--(A);

\node[var, below right of = B](A2){A};
\node[var, below left of = A2](B2){B};
\node[var, below right of = A2](C2){C};
\draw[->] (B2)--(A2);
\draw[->] (A2)--(C2);
\draw[->] (C2)--(B2);
\end{tikzpicture}  
\end{document}