Why are the dimensions of objects not the same between those shown on the workplane, after you place an object (eg a ring) and in the shape menu - the former uses diameter and the latter radius, which - for some, fiddly sizes - need a calculator to switch between. Why not just use diameter? And once you start resizing on the workplane, the values in the shape menu sometimes stop meaning anything at all.
Radius or diameter? Pick one, please!