I want to add some numbers at 3 places in Venn program. But I don't know how to do that.
\documentclass{letter}
\usepackage[english]{babel}
\usepackage{tikz}
\def\secondcircle{(210:1.75cm) circle (2.5cm)}
\def\thirdcircle{(330:1.75cm) circle (2.5cm)}
\begin{document}
\begin{tikzpicture}
\begin{scope}
\clip \secondcircle;
\fill[cyan] \thirdcircle;
\end{scope}
\draw \secondcircle node [text=black,below left] {$B$};
\draw \thirdcircle node [text=black,below right] {$C$};
\end{tikzpicture}
\end{document}





\node at (0,0) {zero};is for the origin (0,0). The other coordinates you can obtains using polar coordinates. For example, the center of the left circle has angle 210 and radius 1.75. If you change the angle you can pass to other points inside the white area. – Sigur Dec 29 '13 at 14:58