答案1
尝试子字幕包。以下代码产生下面的输出。
\documentclass{article}
\usepackage{tikz} % just for the boxes
\usepackage{subcaption}
\begin{document}
\begin{figure}\centering
\begin{subfigure}[b]{4.2cm}
\tikz\draw(0,0)rectangle(4,9);
\caption{Caption1}\label{fig:1}
\end{subfigure}
\quad
\begin{tabular}[b]{@{}c@{}}
\begin{subfigure}[b]{4.2cm}
\tikz\draw(0,0)rectangle(4,4);
\caption{Caption2}\label{fig:2}
\end{subfigure}\\
\begin{subfigure}[b]{4.2cm}
\tikz\draw(0,0)rectangle(4,4);
\caption{Caption3}\label{fig:3}
\end{subfigure}
\end{tabular}
\caption{Main caption}\label{fig:main}
\end{figure}
\end{document}