\documentclass{article}

\usepackage{geometry}
\usepackage[dutch]{babel}
\usepackage{parskip}
\usepackage{amsmath,amssymb}
\usepackage{adjustbox}
\usepackage{xcolor}

\geometry{
	paperwidth=9cm,
	paperheight=7.5cm,
	margin=0.0cm,
	paperheight=3cm,
	paperheight=2cm,
    %paperwidth=4cm,
    paperheight=3cm
}

\counterwithin{equation}{section}

\begin{document}
    Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nullam consequat mi sed nisl ultrices
    tempor. 

    \adjustbox{
        cframe=blue!50!white 1pt 6pt 3pt,
        bgcolor=blue!10!white,
    }{%
        \parbox{\dimexpr\linewidth - 20pt\relax}{
            Quisque porta feugiat tortor tristique porta.
            Morbi fermentum egestas felis finibus tincidunt.
        }%
    }
\end{document}