Adding text to circle in TikZ

Question

I drew a circle and wanted to add text $T_1$ inside it:

\draw (0,0) circle [radius=0.3] {$T_1$};

Why does this not work, and how can I fix it?

Answer 1

Use a node to add the label

\draw (0,0) circle [radius=0.3] node {$T_1$};

or use a \node with circle shape:

\documentclass{article}
\usepackage{tikz}

\begin{document}

\begin{tikzpicture}
\draw (-2,-2) grid (3,3);
\draw (0,0) circle [radius=0.3] node {$T_1$};
\node[draw,circle,minimum size=1cm,inner sep=0pt] at (2,0) {$T_1$};
\end{tikzpicture}

\end{document}