How can I do this angle symbol?

Question

How can I make the angle symbol with LaTeX?

Answer 1

The symbol in the picture seems to have been built from the “less than” symbol and a parenthesis. I also present an alternative.

\documentclass{article}
\usepackage{amsmath}
\usepackage{amssymb}% for \sphericalangle

\newcommand{\arcangle}{%
  \mathord{<\mspace{-9mu}\mathrel{)}\mspace{2mu}}%
}

\begin{document}

$\arcangle ABC=45^\circ$

$\sphericalangle ABC=45^\circ$

\end{document}

If you want the symbol centered with respect to capital letters:

\documentclass{article}
\usepackage{amsmath}

\newcommand{\arcangle}{\mathord{\mathpalette\doarcangle\relax}}
\newcommand{\doarcangle}[2]{%
  \hbox{%
    \sbox0{$#1B$}%
    \sbox2{$#1<$}%
    \raisebox{\dimexpr\dp2+(\ht0-\ht2)/2}{%
      $#1<\mspace{-9mu}\mathrel{)}\mspace{2mu}$%
    }%
  }%
}

\begin{document}

$\arcangle ABC=45^\circ$

\end{document}