What is "Mutzak"?
Refer to Melachim I, 7:23:2:1
What is "from edge to edge"?
'Rashi': It is in the middle (from one edge to the opposite edge). The width of a circle is in its middle.
What is "v'Kav"?
'Rashi' (citing Eruvin 14b): It is the circumference; it is three times the diameter.
What is "Komaso"?
'Rashi': It is its depth.
'Rashi' (citing Eruvin 14b) writes that the circumference is three times the diameter. This is not precise!
Tosfos ha'Rosh (14b): The verse is a source that we may rely on this approximation, which is not exact. 1
The exact ratio of the circumference to the diameter is ? (Pi) - 3:1415926?; the ratio of the Gematriyos (adding one for the word itself) of "v'Chamesh" (355) and "v'Kav" (113) is 3:1415929?, within one part in a million of the exact value of ?. There is no better approximation for ? that is the ratio of Gematriyos [of two words], or of any other whole numbers less than 10,000. There is a superfluous 'Hei' in v'Kav in Melachim I, 7:23 - perhaps this alludes to taking the ratio of this word and v'Chamesh. Alternatively, the ratio of the Gematriyos of 'v'Kav' with and without the Hei is 118/113 = 1.045?, extremely close to the correction factor (the circumference is really ?/3 = 1.04719/?times as big as the verse says it is. If we exclude the prefix Vov, the ratio, i.e. 111/106 = 1.04717, is extremely close. (PF. The basis for this was heard in the name of the Vilna Gaon.)
Sha'ar ha'Tziyun 372:18: Perhaps there is a tradition from Sinai to rely on this, and that a square's diagonal is seven fifths of its side, for it is tedious to be precise.
