How to use both margins of the page for a good positioning of the figures?

Question

I have three figures, and have put them together as follows:

\documentclass[11pt]{article}
\begin{figure}
\centering
\includegraphics[width = 0.7\textwidth]{AA.pdf}\enspace
\includegraphics[width = 0.7\textwidth]{CC.pdf}
\medskip
\includegraphics[width = 0.7\textwidth]{DD.pdf}
\caption{}
\end{figure}

which results in:

I need to keep the size of the figures as they are, that is, I cannot reduce 0.7. Is there any possibility that I can use the left margin of the page and put the two pictures in the first row in the middle of the page in a way that they use both margins?

Answer 1

Set the side-by-side images in a zero-width box (using either \makebox[0pt]{...} or \leavevmode\clap{...}:

\documentclass{article}
\usepackage{graphicx}
\begin{document}
\begin{figure}
  \centering
  \makebox[0pt]{%
    \includegraphics[width = 0.7\textwidth]{example-image-a}\enspace
    \includegraphics[width = 0.7\textwidth]{example-image-b}%
  }%
\medskip
\includegraphics[width = 0.7\textwidth]{example-image-c}
  \caption{}
\end{figure}
\end{document}

Note the use/location of %.

Answer 2

Since you want to have several figures inside a single figure environment, you should make them subfigures:

\documentclass{article}
\usepackage[a4paper]{geometry}
\usepackage{graphicx}
\usepackage{caption}
\usepackage{subcaption}
\begin{document}
\begin{figure}[!htb]
\centering
    \begin{subfigure}[b]{0.45\textwidth}
    \centering
    \includegraphics[width=6cm]{example-image-a}
    \end{subfigure}
\quad
    \begin{subfigure}[b]{0.45\textwidth}
    \centering
    \includegraphics[width=6cm]{example-image-b}
    \end{subfigure}
\medskip
\begin{subfigure}[b]{0.45\textwidth}
\centering
\includegraphics[width=6cm]{example-image-c}
\end{subfigure}

\caption{The caption.}
\end{figure}
\end{document}