todd schreef
Since you're assuming that the round post has the center of the tree as
it's center, I'll assume that the square post is the same.

+ + +
From a practical point of view this assumption is not realistic.
A round post is likely to be 'whole tree'
A square post is likely to be sawn from a bigger trunk.

This means that a round post consists partly of juvenile wood, a weakening
factor. A square post will consist of mature wood.
Ergo: the strength of the material will not be equal in these two cases. It
will be less in a round post
PvR