Create similar triangles symbol

Question

In my country, the similar triangle symbol is different to \cong or \sim symbol. I draw the symbol with TikZ package so it is not compatible with sizes and color. Please help me create the symbol with TeX command. Thank you very much.

P.S The code draws similar symbol.

\documentclass[tikz,border=2mm]{standalone}

\begin{document}

\begin{tikzpicture}[baseline=-7pt,scale=0.1,line width=0.65pt]

\draw (-2,0);
\draw (4,0);
\draw (0,0) arc (90:270:1)..controls +(0:1) and +(180:1).. (2,0) arc (90:-90:1);

\end{tikzpicture}

\end{document}

Answer 1

If you like your tikz symbol there is another simple option. You can wrap it inside a macro and use scalable units. Something like this:

\documentclass{article}
\usepackage   {tikz}

\newcommand{\similar}
{%
  \mathrel%
  {%
    \begin{tikzpicture}[baseline=(a.south),line width=0.15ex]
      \node (a) {};
      \draw (0,0.5ex) arc (90:270:0.5ex) .. controls +(0:0.5ex) and +(180:0.5ex) .. (1ex,0.5ex) arc (90:-90:0.5ex);
    \end{tikzpicture}
  }
}

\begin{document}
The red triangles {\color{red} $ABC \similar DEF$} are similar.

So are the big triangles {\large $A'B'C' \similar  D'E'F'$}.
\end{document}

Edit: As Davislor suggested I wrapped all in a \mathrel for a better spacing.

Answer 2

∽ (U+223D) is \backsim in the packages unicode-math, stix or stix2.

You could instead put a sans-serif S inside a \rotatebox from graphicx.

You can also put a tikzpicture inside \mathrel and use it as a relation symbol in math mode.