\documentclass{article}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{amsfonts}

\thispagestyle{empty}
\begin{document}
\[
c = \sqrt{(205.5\,cr)^2 + (274\,cr)^2} = \sqrt{117\,306.25\,cr^2} = 342.5\,cr
\]
\end{document}
