# Label intersection of 3 sets

I want to make venn diagram using latex, here i already made :

\documentclass[tikz,border=10pt]{standalone}
\usetikzlibrary{positioning,backgrounds}

\begin{document}

\def\firstcircle{(0,0) circle (1.5cm)}
\def\secondcircle{(60:2.1cm) circle (1.5cm)}
\def\thirdcircle{(0:2.1cm) circle (1.5cm)}

\begin{tikzpicture}

\draw \firstcircle node[below] {$1$};
\draw \secondcircle node [above] {$2$};
\draw \thirdcircle node [below] {$3$};

\node [text=black] at (30:20mm) {2};
\node [text=black, anchor=west, xshift=-2mm] at (90:10mm) {1};
\node (m) [text=black, below] at (0:10.5mm) {3};

\end{tikzpicture}
\end{document}


My Question : How to label in the intersection of first, second and the third circle (or otherwise at your discretion) ?

• Welcome to tex.sx ! Just put nodes at the midway of pairs of centers, using a \path (a)--(b) node [midway] {text}; or using the calc tikzlibrary. (Sorry I can't answer I'm on atablet) Aug 7, 2017 at 0:14
• For the intersection of the three circles it is at the 2/3 [pos=.667] between (c) and that midway node (ab). Aug 7, 2017 at 0:21
• thank you for your comment but it still doesn't work, I got error Aug 7, 2017 at 0:31
• This has been answered before. For example, check this . Aug 7, 2017 at 0:47

\documentclass[12pt,tikz]{standalone}
\begin{document}
\def\r{1}
\def\R{1.3}
\begin{tikzpicture}[scale=1.5]
\foreach\ang/\name in {-150/a,-30/b,90/c} \draw (\ang:\r) circle (\R) coordinate (\name) node {\name};
\path (a) -- (b) node [midway] (ab) {ab} ;
\path (b) -- (c) node [midway] (bc) {bc} ;
\path (c) -- (a) node [midway] (ca) {ca} ;
\path (c) -- (ab) node [pos=.667] (abc) {abc}; % actually (abc) is at (0,0) in this config !
\end{tikzpicture}
\begin{tikzpicture}[scale=1.5]
\foreach\ang/\name in {-150/a,-30/b,90/c} \draw (\ang:\r) circle (\R) coordinate (\name) node {\name};
\path (a) -- (b) coordinate [midway] (ab) ;
\path (b) -- (c) coordinate [midway] (bc) ;
\path (c) -- (a) coordinate [midway] (ca) ;
\path (c) -- (ab) coordinate [pos=.667] (abc) node [pos=.667] {abc};
\path (abc) -- (a) node [pos=-.75] {ab} ;
\path (abc) -- (b) node [pos=-.75] {bc} ;
\path (abc) -- (c) node [pos=-.75] {ca} ;
\end{tikzpicture}
\end{document}

• I want to use number to label the venn diagram but when i change the letter becomes number, it looks worse.... thanks Aug 7, 2017 at 1:34
• I am a beginner in latex and I do not understand many things Aug 7, 2017 at 1:35

A code with the dedicated package:

    \documentclass[svgnames]{article}
\usepackage{venndiagram}

\begin{document}

\begin{venndiagram3sets}[labelA= ,labelB= , labelC= ,radius=2cm, overlap=2cm]%
\fillACapBCapC
\setpostvennhook
{%
\draw (labelA) ++(-120:1.8cm) node{$A$};
\draw (labelB) ++(-60:1.8cm) node{$B$};
\draw (labelC) ++(90:1.2cm) node{$C$};
\draw (labelABC) ++(90:0.2cm) node{$A\cap B\cap C$};
}%

\end{venndiagram3sets}

\end{document}


When I was reading about probabilities long time ago, I've written these notes as a tool to simplify multi-events interactions via visualizing them. I hope you find them helpful.

\documentclass{article}
\usepackage{tikz}
\usepackage{geometry}
\geometry{ a4paper,total={170mm,257mm},left=20mm,top=20mm}

\begin{document}
% Definition of circles
\def\firstcircle{ (0.0, 0.0) circle (1.5)}
\def\secondcircle{(2.0, 0.0) circle (1.5)}
\def\thirdcircle{ (1.0,-1.5) circle (1.5)}
\def\rectangle{ (-1.5,-3.0) rectangle (3.5,1.0) }
\colorlet{circle edge}{black}
\colorlet{circle area}{blue!30}

\tikzset{filled/.style={fill=circle area, draw=circle edge, thick},
outline/.style={draw=circle edge, thick}}

\setlength{\parskip}{5mm}
%############################################################################
%############################################################################
%############################################################################
\noindent
\begin{tikzpicture}
\begin{scope}
\clip  \firstcircle;
\clip  \secondcircle;
\fill[filled]   \thirdcircle ;
\end{scope}
\draw[outline] \firstcircle  node[left]  {$A$};
\draw[outline] \secondcircle node[right] {$B$};
\draw[outline] \thirdcircle  node[below] {$C$};
\node[anchor=south] at (current bounding box.north) {$A \cap B \cap C$};
%############################################################################
%############################################################################
%############################################################################
\begin{tikzpicture}
\begin{scope}
\clip \firstcircle \secondcircle \thirdcircle;
\fill[filled]  \firstcircle \secondcircle \thirdcircle;
\end{scope}
\draw[outline] \firstcircle  node[left]  {$A$};
\draw[outline] \secondcircle node[right] {$B$};
\draw[outline] \thirdcircle  node[below] {$C$};
\node[anchor=south] at (current bounding box.north) {$A \cup B \cup C$};
%############################################################################
%############################################################################
%############################################################################
\begin{tikzpicture}
\begin{scope}
\clip \firstcircle;
\fill[filled] \secondcircle;
\end{scope}
\draw[outline] \firstcircle  node[left]  {$A$};
\draw[outline] \secondcircle node[right] {$B$};
\draw[outline] \thirdcircle  node[below] {$C$};
\node[anchor=south,align=center] at (current bounding box.north)
{$(A\cap B)=$\\$(A \cap B \cap C) + (A \cap B \cap C')$};
\end{tikzpicture} \\[1.5cm]
%############################################################################
%############################################################################
%############################################################################
\begin{tikzpicture}
\begin{scope}
\clip \firstcircle;
\fill[filled] \thirdcircle;
\end{scope}
\begin{scope}
\clip \firstcircle;
\clip \secondcircle;
\fill[white] \thirdcircle;
\end{scope}
\draw[outline] \firstcircle  node[left]  {$A$};
\draw[outline] \secondcircle node[right] {$B$};
\draw[outline] \thirdcircle  node[below] {$C$};
\node[anchor=south] at (current bounding box.north)
{$(A\cap B' \cap C)$};
%############################################################################
%############################################################################
%############################################################################
\begin{tikzpicture}
\begin{scope}
\fill[filled] \thirdcircle;
\fill[white]  \firstcircle;
\fill[white]  \secondcircle;
\end{scope}
\draw[outline] \firstcircle  node[left]  {$A$};
\draw[outline] \secondcircle node[right] {$B$};
\draw[outline] \thirdcircle  node[below] {$C$};
\node[anchor=south] at (current bounding box.north)
{$(A' \cap B' \cap C)$};
%############################################################################
%############################################################################
%############################################################################
\begin{tikzpicture}
\begin{scope}
\clip \secondcircle;
\fill[filled] \thirdcircle;
\end{scope}
\fill[filled]  \firstcircle;
\draw[outline] \firstcircle  node[left]  {$A$};
\draw[outline] \secondcircle node[right] {$B$};
\draw[outline] \thirdcircle  node[below] {$C$};
\node[anchor=south] at (current bounding box.north)
{$A \cup (B \cap C)$};
\end{tikzpicture} \\[1.5cm]
%############################################################################
%############################################################################
%############################################################################
\begin{tikzpicture}
\begin{scope}
\clip \firstcircle \secondcircle;
\fill[filled] \thirdcircle;
\end{scope}
\draw[outline] \firstcircle  node[left]  {$A$};
\draw[outline] \secondcircle node[right] {$B$};
\draw[outline] \thirdcircle  node[below] {$C$};
\node[anchor=south] at (current bounding box.north)
{$(A \cup B) \cap C$};

\end{document}


There's a package for this!

\documentclass{article}
\usepackage{venndiagram}
\usepackage[margin=1in]{geometry}
\begin{document}
\begin{venndiagram3sets}[labelABC={\raisebox{10ex}{$A\cap B \cap C$}},tikzoptions={scale=3,thick}]
\end{venndiagram3sets}
\end{document}