\documentclass[11pt]{article}

\usepackage[
  showframe,
  marginparwidth=0cm,
  marginparsep=0cm,
  left=0.75in,
  right=0.75in,
  top=0.75in,
  bottom=0.75in]{geometry}

  \begin{document}
  \begin{center}
    \Huge lallalalalalal\\
  \end{center}
\end{document}