Making a custom angle symbol

Question

I want to create a mathematical symbol as below.

This symbol should be exactly the same as the usual \angle command (with the amsfonts package) in terms of dimensions: it should not be wider or taller. It should have the same 'arc' as in \measuredangle (but not its dimensions, since this is taller). And of course, it should be filled with gray: \color{gray} (with the xcolor package). I want to be able to use it in an equation like \(\filledangle ABC\), identical to how commands like \angle are used. How can I do this? I have a sense that I would perhaps need to define a macro perhaps using tikz; but I have no clue where to start.

I can draw the figure by itself quite easily. Consider the following MWE:

\documentclass{article}
\usepackage{tikz}

\begin{document}
    \begin{tikzpicture}
    \draw[fill=gray] (0,0) -- +(45:2) arc (45:0:2) -- (0,0);
    \draw (0,0)--(45:3) (0,0)--(0:3);
    \end{tikzpicture}
\end{document}

This produces something similar to what I want, but I am not sure that this is the correct scale used in \angle, nor do I know how to get this into the form of a command in math mode or how to get it to scale correctly.

P.S. This symbol should scale properly and be of the correct relative size to the math beside it; e.g. if I type \(x^{\filledangle ABC}\) for whatever reason, the symbol should turn smaller accordingly. Thanks in advance!

Answer 1

I hope to have understood your question. By changing the coordinates you can adjust the angle as you wish.

\documentclass{article}
\usepackage{tikz,xcolor}
\usetikzlibrary{quotes,angles}
\newcommand{\comangle}[1]{%
\begin{tikzpicture}
    \draw coordinate (a) at (0.3,0);
    \draw coordinate (b) at (0,0);
    \draw coordinate (c) at (.2,0.25);
    \draw (a) -- (b) -- (c) pic [draw=black,fill=gray!50,angle radius=.2cm] {angle=a--b--c};
\end{tikzpicture}%
}
\begin{document}
\comangle{} your new symbol.

\end{document}

VARIATION

\documentclass{article}
\usepackage{tikz,xcolor}
\usetikzlibrary{quotes,angles}
\newcommand{\comangle}{\kern.08em%
\begin{tikzpicture}
    \draw coordinate (a) at (0.15,0);
    \draw coordinate (b) at (0,0);
    \draw coordinate (c) at (.14,0.25);
    \draw (a) -- (b) -- (c) pic [draw=black,fill=gray!50,angle radius=.11cm] {angle=a--b--c};
\end{tikzpicture}%
\kern.08em%
}
\begin{document}
$\angle A$

$\comangle A$

\end{document}