DB: This makes no sense. The 95 degree angle (which by the way I have calculated to be a bit higher) has no bearing on the size of the square at all.
If the angle between L1 and the diagonal were 90 degrees (see above), G3 would be square (green dotted line). Also, keep in mind here that we have already defined the length of the diagonal.
That the angle between L1 and the known diagonal is 95.5 degrees must result in G3 being a slight rectangle (green dotted line). Not only this but what we find is that by placing the diagonal of our set-square (large red box) through the diagonal (L2) results in the peculiar angles of the western and northern flanks of G3 (see below).
Post Edited (10-Feb-12 11:25)