%!TEX pdflatex
\documentclass{article}
\usepackage{tikz}
\usepackage{pgf,pgffor}
\usepackage{siunitx}
\sisetup{locale=FR}
\begin{document}
\tikz \draw[thick,rounded corners=8pt] (0,0) -- (0,2) -- (1,3.25) -- (2,2) -- (2,0) -- (0,2) -- (2,2) -- (0,0) -- (2,0);
\end{document}