36º. Just kidding... need more info. how big is the
stage, how high is the ladder, how many zones are you breaking it up into?
You can figure it out for yourself by making a scale drawing of the
theatre in elevation view (front view, how the audience sees it). Then
overlay various
barrel angles (19, 26, 36, 50º) and see what will give you the best coverage. I go through this process in
Vectorworks for each show, it's called worksheeting. Often you end up with something like a near, a mid, and far shot that might be a 50, a 36, and a 26, respectively. Depends on the
theatre, the show, and the scenery.