His eyes keep down-turned, focused on the circle he's drawing. Oliver doesn't usually do shit that requires this amount of focus; relying on sacred geometry is shit he only does on occasion, so he's being careful not to fuck up his lines. The chalk hits the end of the circle, and Oliver's pulling it back to start on a large triangle that intersects the outermost circles.

"A phone with GPS'd make this a lot easier, actually. Was it theirs, or did they just fuck with it?" Not that he's waiting for an answer, because Oliver's extending a hand out over the table, palm up.