[Tex/LaTex] Figure with two columns, one subfigure on the first column, two on the second column

Question

How can I have a figure (with a caption) that has three subfigures (each with its own caption, say (a), (b) and (c)) with the following layout: There are two columns; the first column is a single subfigure, the second column consists of two subfigures stacked vertically:

Answer 1

Using subcaption and minipages you can achieve this:

\documentclass[]{article}

\usepackage{subcaption}
\usepackage[]{graphicx}

\begin{document}
\begin{figure}% >>>
  \centering
  \begin{minipage}[t]{.45\linewidth}
    \subcaptionbox{text1}
      {\includegraphics[width=\linewidth]{example-image-duck}}%
  \end{minipage}%
  \hfill
  \begin{minipage}[b]{.45\linewidth}
    \subcaptionbox{text2}
      {\includegraphics[width=.5\linewidth]{example-image-duck}}
    \subcaptionbox{text3}
      {\includegraphics[width=.5\linewidth]{example-image-duck}}%
  \end{minipage}%
  \caption
    {%
      Caption.%
      \label{fig:caption}%
    }%
\end{figure}% <<<

\end{document}

Using the subfig package as though one has tried to read its manual:

\documentclass[]{article}

\usepackage{subfig}
\usepackage[]{graphicx}

\begin{document}
\begin{figure}% >>>
  \centering
  \begin{minipage}[t]{.45\linewidth}
    \subfloat[text1]
      {\includegraphics[width=\linewidth]{example-image-duck}}%
  \end{minipage}%
  \hfill
  \begin{minipage}[b]{.45\linewidth}
    \subfloat[text2]
      {\includegraphics[width=.5\linewidth]{example-image-duck}}\\
    \subfloat[text3]
      {\includegraphics[width=.5\linewidth]{example-image-duck}}%
  \end{minipage}%
  \caption
    {%
      Caption.%
      \label{fig:caption}%
    }%
\end{figure}% <<<

\end{document}

Output is almost identical.