What if my intermediate dimensions do not add up to what my overall dimension
Select Edit > Edit Item and edit the walls from which the extensions/dimension are pulling from.
It is possible that the walls were not drawn in with the lock on, which would allow the wall to be a single degree
or so off. To avoid drawing a wall without lock, be sure that the Snap feature is not enabled. The snap can be
enabled/disabled by either selecting the icon or the menu Tools > Snap or F11.