File:Hausdorff property in metric spaces.svg

\documentclass[tikz,border=8pt]{standalone}
\usetikzlibrary{calc}
\usepackage{amsmath}
\begin{document}
\begin{tikzpicture}[scale=1.3]
% Radius of the open balls
\def\r{1.5}

\coordinate (x) at (0,0);

% The angle between the two open balls
\def\ang{20}

\coordinate (y) at ({2*\r*cos(\ang)}, {2*\r*sin(\ang)});

\draw[fill=blue!25!cyan, opacity=0.2, dashed, thick] (x) circle (\r);
\draw[fill=blue!25!cyan, opacity=0.2, dashed, thick] (y) circle (\r);

\fill (x) circle (2pt);
\fill (y) circle (2pt);

\node[below left] at (x) {$x$};
\node[above right] at (y) {$y$};

% Radius with label
\draw[black, dashed, thick]
(x) -- ({\r*cos(\ang)}, {\r*sin(\ang)})
node[midway, above, sloped] {\footnotesize $r=\dfrac{d(x,y)}{2}$};

\end{tikzpicture}
\end{document}