I use \usepackage{fouriernc}. Now, I want to select the font chancery for theorem environment. How can I choose the font for an environment, for example, theorem environment?
\documentclass{book}
\usepackage{amsmath,amsthm}
\usepackage{fouriernc}
\newtheorem{theorem}{Theorem}
\usepackage{lipsum}
\begin{document}
\chapter{These Real Numbers}
\lipsum[1-2]
\begin{theorem}
\fontfamily{qzc}\selectfont\large
This is a theorem Pythagore
$$a^2 + b^2 = c^2.$$
\end{theorem}
\end{document}
How can I input \fontfamily{qzc}\selectfont\large at \newtheorem{theorem}{Theorem} before \begin{document}?