Distance measurement in a square

[Wes Armour]

Hi All,

I have some images of square objects. I would like to measure the
edge-to-edge distance of the square at any given orientation of the
square and would like to do this many times within each square. So in
effect it would be like slicing the square up at regular intervals for a
given angle. Is there a plug-in that could do this???

Thanks for any help,

Wes.