Panel Figure 2x2!

Question

How do the beamer a panel with 4 figure (2 x 2). As the following example:

Answer 1

Improve this code:

  \documentclass{beamer}
  \usetheme{default}

 \begin{document}
 \begin{frame}{Panel figure 2 x 2!}
   \begin{minipage}{1\textwidth}
    \includegraphics[scale = 0.3]{example-image}
    \hfill
    \includegraphics[scale = 0.3]{example-image}
    \vspace{0.5cm}
    \includegraphics[scale = 0.3]{example-image}
    \hfill
    \includegraphics[scale = 0.3]{example-image}
  \end{minipage}

    Figure 1: \ldots
 \end{frame}

 \end{document}