\documentclass[12pt]{jsarticle}
\usepackage{amsmath,amssymb}
\pagestyle{empty}
\begin{document}
\setlength{\baselineskip}{22pt}
\begin{flushleft}
{\huge 2}
　$\alpha$，$\beta$が$\alpha>0^\circ$，$\beta>0^\circ$，$\alpha+\beta<{180}^\circ$かつ
$\sin^2\alpha+\sin^2\beta=\sin^2(\alpha+\beta)$を満たすとき，
$\sin\alpha+\sin\beta$の取りうる範囲を求めよ．
\end{flushleft}
\end{document}
