How create circle node in Tikz with T from lines inside? T made split node to 3 sectors

Question

I woud like create 3 sector circle node. See the following figure

sectors are bounded by lines

Answer 1

Update 2

I think better than my first version is to use a style. I added with the last update the possibility to modify the style for the intern nodes.

\documentclass[11pt]{scrartcl}
\usepackage{tikz}
%\usetikzlibrary{shapes} now not necessary
\begin{document}

\tikzset{sectors/.style n args={5}{%
  circle,
  draw,
  minimum width=#4,
  append after command={%
  \pgfextra{ %
   \draw (\tikzlastnode.center) -- (\tikzlastnode.south) ;
   \draw (\tikzlastnode.west)   -- (\tikzlastnode.east) ;
   \path (\tikzlastnode.center) -- node[#5] {#1} (\tikzlastnode.north);  
   \path (\tikzlastnode.center) -- node[#5] {#2} (\tikzlastnode.south west); 
   \path (\tikzlastnode.center) -- node[#5] {#3} (\tikzlastnode.south east); } }}}

\begin{tikzpicture}[ultra thick]
  \node [sectors={1}{2}{3}{4cm}{font=\Huge\bfseries,text=red}]  (c)  {};
\end{tikzpicture}

\end{document} 

Another idea

\documentclass[11pt]{scrartcl}
\usepackage{tikz}
\usetikzlibrary{shapes}
\begin{document}

\begin{tikzpicture}[ultra thick]
  \node [circle split,
         draw,
         minimum width=4cm,
         append after command={%
         \pgfextra{\draw (\tikzlastnode.center) -- (\tikzlastnode.south) ;
                  } 
                  }]  (c)  {};
  \node[yshift=2em] at (c.center) {\huge \textbf{1}};  
  \node[xshift=-2em,yshift=-2em] at (c.center) {\huge \textbf{2}}; 
  \node[xshift= 2em,yshift=-2em] at (c.center) {\huge \textbf{3}};  
\end{tikzpicture}

\end{document} 

Answer 2

You can do something like this:

\documentclass{article}
\usepackage{tikz}

\newlength\radius
\setlength\radius{7mm}

\begin{document}

\begin{tikzpicture}
\draw circle (\radius);
\draw +(-\radius,0) -- +(\radius,0);
\draw +(0,-\radius) -- +(0,0);
\node[font=\Large\sffamily] at (0,0.5\radius) {1};
\node[font=\Large\sffamily] at (-0.35\radius,-0.5\radius) {2};
\node[font=\Large\sffamily] at (0.35\radius,-0.5\radius) {3};
\end{tikzpicture}

\end{document}

Now that I re-read the question, I see that you wanted tp use a \node for the circle, so here's some possible solution using \node:

\documentclass{article}
\usepackage{tikz}

\newlength\diam
\setlength\diam{14mm}

\begin{document}

\begin{tikzpicture}
\node[draw,circle,inner sep=0pt,minimum width=\diam] (circ) {};
\draw (circ.180) -- (circ.0);
\draw (circ.270) -- +(0,0.5\diam);
\node[font=\Large\sffamily,yshift=0.25\diam] at (circ.center) {1};
\node[font=\Large\sffamily,xshift=-0.18\diam,yshift=-0.25\diam] {2};
\node[font=\Large\sffamily,xshift=0.18\diam,yshift=-0.25\diam] {3};
\end{tikzpicture}

\end{document}

Answer 3

Here, two solutions: first is directly derived from Gonzalo Medina's solution. Second uses a more "robust" technique (via fit library): materials may not exceed the circle.

\documentclass{standalone}
\usepackage{tikz}
\usetikzlibrary{positioning,fit}

\begin{document}
\begin{tikzpicture}
  \node[draw,circle,inner sep=0pt,minimum width=3.5em] (circ) {};
  \draw (circ.180) -- (circ.0);
  \draw (circ.270) -- (circ.center);
  \path (circ.center) -- node{1}(circ.90);
  \path (circ.center) -- node{2}(circ.-135);
  \path (circ.center) -- node{3}(circ.-45);
\end{tikzpicture}
\begin{tikzpicture}
  \coordinate (center) at (0,0);
  \node[above=0mm of center](p1){1};
  \node[below left=0mm of center](p2){2};
  \node[below right=0mm of center](p3){3};
  \node[draw,inner sep=0pt,circle,fit=(p1)(p2)(p3)](c){};
  \draw (center) -- (c.0);
  \draw (center) -- (c.180);
  \draw (center) -- (c.-90);
\end{tikzpicture}
\end{document}

Answer 4

[fr] il me semble qu'aucune des solutions proposées n'est robuste

il est nécessaire de modifier légérement la 2eme solution de PolGab pour obtenir une solution qui s'adapte au nombre de caractères en précisant le centre du noeud

[en] it seems to me that none of the solutions proposed is robust

it is necessary to modify slightly the 2nd PolGab solution to obtain a solution that adapts to the number of characters specifying the center of the node

\documentclass{standalone}
\usepackage{tikz}
\usetikzlibrary{positioning,fit}

\begin{document}

\begin{tikzpicture}
  \coordinate (center) at (0,0);
  \node[above=0mm of center](p1){1};
  \node[below left=0mm of center](p2){2};
  \node[below right=0mm of center](p3){3};
  \node[draw,inner sep=0pt,circle,fit=(p1)(p2)(p3)](c)at (center){};
  \draw (center) -- (c.0);
  \draw (center) -- (c.180);
  \draw (center) -- (c.-90);
\end{tikzpicture}
\begin{tikzpicture}
  \coordinate (center) at (0,0);
  \node[above=0mm of center](p1){1};
  \node[below left=0mm of center](p2){2};
  \node[below right=0mm of center](p3){312};
  \node[draw,inner sep=0pt,circle,fit=(p1)(p2)(p3)](c)at (center){};
  \draw (center) -- (c.0);
  \draw (center) -- (c.180);
  \draw (center) -- (c.-90);
\end{tikzpicture}

\end{document}