
\documentclass{article}
\usepackage[body={8cm,8cm}]{geometry}
\usepackage{lmodern}
\pagestyle{empty}
\begin{document}
Comparez les parenthèses~:
\[
(\frac{1}{2}) = 
    \left( \frac{2}{4} \right) 
\]
\end{document}
