latex keepaspectratio documentation code example
Example: latex width figure
\documentclass{report}
\usepackage[english]{babel}
\usepackage{graphicx}
\begin{document}
\includegraphics[height=3cm]{example-image-b}
\includegraphics[width=5cm]{example-image-b}
\includegraphics[height=3cm, width=3cm]{example-image-b}
\includegraphics[height=3cm, width=6cm]{example-image-b}
\includegraphics[keepaspectratio,height=3cm, width=6cm]{example-image-b}
\end{document}