Actually we use horizontal offset because it is more intuitive. Angles are deceptive for very tall buildings. You end up with a tiny angle eg 0.1deg that it sounds too small.
Also what people don't realize that the swing at the top floor of such a tall building due to wind may be actually about also another foot at worst case.
Also what people don't realize that the swing at the top floor of such a tall building due to wind may be actually about also another foot at worst case.