"The diameter is 10 cubits ,the circumference would have to be 31.4159 cubits (circumference =pi x diameter )" ?
Smiddy, please read my post above. It can not be the same circle that is measured, the diameter across of the vessel, is rim to rim, is bigger than the lower measurement of the container just below it, like the rim on a cup.
Thank you Fisherman, for the illustration it is impossible to stretch a measuring line (scotch tape was not invented yet) along that thin edge at the top, 31. 4--- long, but easy above the ring of pomegranates, to keep it from slipping down.