I would like to use Glenn from fncychap with polyglossia to looks like the following picture but it doesn't work at all
here's my MNW
\documentclass[12pt,a4paper]{extbook}
%Options: Sonny, Lenny, Glenn, Conny, Rejne, Bjarne, Bjornstrup
\usepackage[Glenn]{fncychap}
\usepackage{polyglossia}
\setmainlanguage[numerals=maghrib]{arabic}
\setotherlanguage{english}
\newfontfamily\arabicfont[Script=Arabic, AutoFakeSlant=-0.02]{Amiri}
\setsansfont[Script=Arabic,Scale=1.5]{Amiri}
\begin{document}
\tableofcontents
\chapter{محسن}
\section{محسن}
\subsection{محسن}
\end{document}


fncychaplast. – touhami Feb 21 '17 at 16:25