Possible Duplicate:
How to place a node in the middle of an arc?
Following the manual where labels are positioned on curves (\draw (0,0) .. controls (6,1) and (9,1) .. node {midway} (12,0);), I thought this must be possible with arcs as well:
\begin{tikzpicture}
\draw (1,0) arc node[midway]{H} (0:180:1);
\end{tikzpicture}
But that doesn't compile at all.
If I use
\draw (1,0) arc (0:180:1) node[midway]{H};
then the label isn't positioned on (or rather above) the arc but just on the bottom line centered. I don't want to manually shift or position it.

I rather want:

Hon the arc, right at the middle. (So that the arc goes through the middle line in the H). – nickpapior Oct 11 '12 at 19:50