% This is file debug1.tex
% Type
%  pdflatex debug1
% for a very basic test of your latex (or pdflatex) installation.  The
% file debug1.log should not contain any error messages and debug1.pdf
% should read correctly in a pdf reader.
%
\documentclass{article}
%
\newcommand\Angle[1]{\setbox0=\hbox{$\mskip 7mu minus 4mu#1$}%
    \raise.21ex\hbox{$/$}\hskip-0.95ex\underline{\raise\dp0\hbox{\box0}}}
%
\begin{document}
  $120\Angle{50^{\circ}}$
\end{document}