Latex beamer two boxes side by side

Question

I want to place two boxes side by side and one box below both of them such that the are aligned. I thought of using columns, but then the alignment does not match.

Here my minimal example:

\documentclass[t,aspectratio=169]{beamer}
\usetheme{boxes}
\usecolortheme{rose}

\begin{document}
\begin{frame}
  \frametitle{test}
  \begin{columns}
    \begin{column}{0.5\linewidth}
      \begin{block}{left}
        text
      \end{block}
    \end{column}
    \begin{column}{0.5\linewidth}
      \begin{block}{right}
        text
      \end{block}
    \end{column}
  \end{columns}
  \begin{block}{middle}
    text
  \end{block}
\end{frame}
\end{document}

with output:

But I would like to get something like this:

What is the best practice for this problem?

While I am writing this the algorithm of this website suggested me some similar posts and in one of these post there was the optional parameter onlytextwidth for the columns environment. But this leads to two touching Blocks. then I can reduce the size of the columns to e.g. 0.48\textwidth which surprisingly works. I expected that then the two blocks don't align on the right hand side.

the column documentation doesn't really tell me how it arranges the columns.

So even though I found kind of a solution I am wondering how the "best" solution looks like.

Answer 1

onlytextwidth is the best solution.

That being said, that's how beamer creates columns:

• without the onlytextwidth option, beamer does not apply left/right margins to the columns and instead uses an \hfill:

  <left margin> normal text <right margin>
  < \hfill > | column 1 | < \hfill > | column 2 | < \hfill >
  

  this means that even if your columns sum up to the whole \textwidth, there will still be space in the middle, but the margins are wrong

• with the onlytextwidth option:

  <left margin> normal text <right margin>
  <left margin> | column 1 | < \hfill > | column 2 | < right margin >
  

  this means if your columns sum up to the whole \textwidth, there is no room left in the middle which \hfill could fill