Typesetting vertical angles

Here's some code for typesetting problems involving vertical angles. The code isn't very flexible, but it works good enough for me. I welcome suggestions for improving this code.


\begin{tikzpicture}
\def\x{5};
\def\y{2.5};
\draw (0,0)--(\x,\y);
\draw (0,\y)--(\x,0);
\node[above=4mm] at ({\x/2},{\y/2}) {$120^\circ$};
\node[below=4mm] at ({\x/2},{\y/2}) {$2x - 10$};
\end{tikzpicture}