\documentclass[a4paper, 11pt]{article}
\usepackage{a4wide}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{helvet}
\usepackage{calc}
\usepackage{color}
\usepackage{graphicx}

\definecolor{thegray}{gray}{.8}
\begin{document}
\thispagestyle{empty}

\newcommand\thetext{\sffamily\fontsize{28}{0}\selectfont\color{thegray} Dummy Page}
\newlength\thewidth
\settowidth\thewidth{\thetext}
\begin{center}
  \resizebox*{!}{\dimexpr\textheight-2\baselineskip\relax}{%
    \rotatebox{285}{
      \parbox{\thewidth}{\thetext}
    }
  }
\end{center}
\end{document}