lemeres |
Actually, it is fairly easy to tell, mostly due to the descriptions.
The description of the greataxe says it is '3 to 4 feet long'. A quick google search says that dane axes meant for battle had hafts that were '3 to 4 feet long'. So that is a fantastic sign. That seems fairly consistent.
Battle axes, by comparison, do not have a stated length. It simply says that it can be wielded in one or two hands. For general purposes, I think it is useful to think of battle axes as edging up to 3 feet, and anything past that goes to great ax length.