I need a help to modify the Arabic font size in this document:

\usepackage{fourier} % math font
\usepackage{polyglossia}% pour arabe





\setmainfont[Ligatures=TeX]{Traditional Arabic}
\setsansfont[Mapping=text-text]{Times New Roman}

\newfontfamily\sectcolor[Color=sectcolor,Script=Arabic]{Traditional Arabic}
\newfontfamily\subsectcolor[Color=subsectcolor,Script=Arabic]{Traditional Arabic}
\newfontfamily\subbsectcolor[Color=subbsectcolor,Script=Arabic]{Traditional Arabic}
\newfontfamily\arabicfont[Color=textcolor,Script=Arabic]{Traditional Arabic}

\usepackage[Lenny ]{fncychap}
\renewcommand{\thesubsection}{\arabic{section} -\arabic{subsection}}
\renewcommand{\thesubsubsection}{\arabic{section} -\arabic{subsubsection}-\arabic{subsection}}



\renewcommand{\headrulewidth}{0  pt}
\renewcommand{\chaptermark}[1]{\markboth{\thechapter\ #1}{}}
\renewcommand{\sectionmark}[1]{\markright{\thesection\ #1}}

\fancyhead {} % on efface l’entête
\fancyfoot{} % on efface le pied de page
\parindent 0pt





\section{مفاهيم أولية}
\subsection{ المصفوفة }
 نسمي مصفوفة كل جدول من الأعداد الحقيقية المرتبة على شكل $m$ سطر و $n$ عمود. الأعداد التي تكون المصفوفة تسمى عناصر (أو معاملات) المصفوفة. المصفوفة ذات $m$ سطر و $n$ عمود تدعى مصفوفة من الرتبة $(m,n)$ أو البعد $m\times n$. نرمز إلى مجموعة كل المصفوفات ذات البعد  $m\times n$ بالرمز $\mathcal{M}_{m\times n}(\mathbb{R})$.


       من ويكيبيديا، الموسوعة الحرة

closed as unclear what you're asking by Thérèse, Kurt, Stefan Pinnow, CarLaTeX, Bobyandbob Feb 5 '18 at 8:17

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  • 1
    did you try [...,Scale=1.8]{Traditional Arabic}? – touhami Feb 3 '18 at 16:45
  • Thanks touhami for ur respond, There is no change. – user154138 Feb 3 '18 at 17:03
  • sorry, but did you try \newfontfamily\arabicfont[Color=textcolor,Script=Arabic,Scale=1.8]{Traditional Arabic}? it works fine for me. – touhami Feb 3 '18 at 18:04
  • 3
    Can you make your example minimal (i.e., load only the packages needed to reproduce the problem) and replace the proprietary fonts with fonts found in TeX Live (e.g., Amiri for Arabic, and TeX Gyre Termes instead of Times New Roman)? That way more of us will be able to help you. – Thérèse Feb 3 '18 at 18:49
  • 1
    I can’t reproduce the problem with Amiri: @touhami’s solution works — unless the Traditional Arabic font is defective, but that would have come to light by now. However, fontspec warns that sectcolor and textcolor are bad color declarations (and since you haven’t loaded xcolor or used the first three of the new font families you’ve defined, it’s not clear what you’re trying to accomplish). You should fix such warnings before proceeding. – Thérèse Feb 4 '18 at 0:57