One new wider circumference [yellow] having the center on the navel
and a ra­di­us sufficient to include the extremity of the hands
when the arms are well raised, it can contain only two shapes:
  1. the legs apart with the feet resting on the circle (yes, those of Le­on­ar­do, as illustrated, but with the right lenght; anyway not by Vitruvius); but I couldn't find out any photos of such a position, among hun­dreds that i browsed!
  2. or the legs ex­tend­ed in an up­right but lying down pos­ture, that is with the feet to­geth­er, nor­mal­ly length­ened, say for about a third in a re­laxed way (as de­scribed by Vi­tru­vi­us, but with­out any di­rect bond­ing be­tween the cir­cle and the square, whose size and lo­ca­tion de­pend sole­ly on the mea­sure­ment of the man, and not the opposite!).
Let's compare some real im­ages:
two upside down with the hands grip­ping the par­al­lels; the feet are ex­tend­ed, all are framed with the un­err­ing pro­por­tions; and please, don't for­get that 'cham­pi­on' means 'ex­cel­lent' as well as 'sam­ple' or 'spec­i­men'… This one would there­fore be the only pos­si­ble way to suit the mod­el out­lined by the great ar­chi­tect, ancient but still lead­er of har­mo­ni­ous pro­por­tions in the de­sign of tem­ples and public buildings (theatres, baths); pri­vate bu­il­d­ings; floors and stucco decoration; hydraulics; clocks, men­su­ra­tion, and astronomy; and civil and military engines.