To format the entire document to landscape formatting:

\documentclass[a4paper,12pt,landscape]{article}

Otherwise:

Use the package ‘lscape’:

Install the package ‘lscape’ of D. Carlisle (LaTeX2e) - lscape source

Insert \usepackage{lscape} at the beginning of document Use \begin{landscape} and \end{landscape} directives to change page orientation

Or use the package ‘rotating’.