They aren't trees. They're supposed to be a surrealish backdrop "sky" that really shouldn't exist due to the sharp perspective. (Hey, I blame Double Dragon)
Believe me, I'll be wasting the other....27 tiles on random crap like doors, signs, garbage cans, and perhaps even cars.
The angles theoretically are correct, according to the perspective, excluding the yellow paint on the roads (I double-checked). They do, however, appear strange. The roof could be higher, but then I'd use up 2 more tiles... heh.
EDIT: I realize that you thought my roof was flat. I should probably make it more apparent that it's a raised roof. I really don't want to use 2 more tiles to make the roof higher... eh, what can I say? I'm a greedy bastard
