My goal is to make a Tikz picture that looks like the example with the white boxes and letters inside.
This is what I did so far (my example has gray boxes). I am not sure how to stack it evenly as in the picture with the white boxes. My LaTeX code is at the bottom... I would then like to output the figure as an image file like a jpeg or tif or png.
\begin{tikzpicture}[>=latex]
\tikzstyle{rect}=[draw=black,
rectangle,
fill=gray,
fill opacity = 0.2,
text opacity=1,
minimum width=100pt,
minimum height = 50pt,
align=center]
\node[rect] (a1) {A};
\node[rect,below right=of a1] (a3) {C};
\node[rect,above right=of a1] (a2) {B};
\draw[->] (a1.north)--(a2.west)node[midway,sloped, above,xshift=-2mm]{1};
\draw[->] (a1.south)--(a3.west)node[midway,sloped, below,xshift=-2mm]{2};
\draw[->] (a2.south)--(a3.north)node[midway, xshift=6mm]{3};
\end{tikzpicture}
\end{figure}
node
commands are putting the rectangles where they end up. Why not monkey around with that to get the arrangement you want? Offhand, it looks like you would want to place C first and then A above left and B above right. Have you not tried that?