\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{decorations, decorations.text, decorations.markings, decorations.pathreplacing, decorations.pathmorphing}
\begin{document}
\tikz \fill [decorate,decoration={crosses}]
[fill=blue!20,draw=blue,thick] (0,0) -- (2,1) arc (90:-90:.5) -- cycle;
\end{document}