\documentclass[landscape,16pt]{article}
\usepackage[latin1]{inputenc}
\usepackage[frenchb,english]{babel}
\usepackage{geometry}
\geometry{paperheight=297mm,paperwidth=223mm,margin=2cm}%%114--162
%\usepackage{sectsty}
% -- For use with sectsy package -- %
%\sectionfont{\Huge}
%\subsectionfont{\LARGE}
%\subsubsectionfont{\Large}
%\paragraphfont{\large\it}
%\subparagraphfont{\normalsize\it}
% -- For use with sectsy package -- %
\usepackage[calcwidth,pagestyles,raggedright,bf,sf]{titlesec}
\titleformat{\section}{\normalfont\Huge\bfseries}{\thesection}{1em}{}
\titleformat{\subsection}{\normalfont\LARGE\bfseries}{\thesubsection}{1em}{}
\titleformat{\subsubsection}{\normalfont\Large\bfseries}{\thesubsubsection}{1em}{}
\titleformat{\paragraph}[runin]{\normalfont\large\bfseries\itshape}{\theparagraph}{1em}{}
\titleformat{\subparagraph}[runin]{\normalfont\normalsize\bfseries\itshape}{\thesubparagraph}{1em}{}
\newpagestyle{main}{%
% \headrule
%\footrule
\sethead[\begin{sideways}\thepage\end{sideways}][][\bfseries\thesection\quad\sectiontitle]{\bfseries\sffamily\thesubsection\quad\subsectiontitle}{}{\begin{sideways}\thepage\end{sideways}}
% \setfoot[][][\scshape Institution]{Title}{}{}
}
\usepackage{lscape}
\usepackage{rotating}
\usepackage{lipsum}
\begin{document}