Talmud su I Re 7:26

“Round, one considers it as if square.¹⁹⁵Mishnah 5.” Again this is Rebbi Jehudah’s¹⁹⁹Since tiles cannot be laid on a round beam, the round beam is unacceptable for the majority.. They inferred it from the sea²⁰⁰The water container in Solomon’s temple. Since the verse there states that its diameter was 10 cubits and its circumference 30, it is inferred that for halakhic computations the ratio of circumference of a circle to diameter is 3 (even though it is obvious that for other computations this cannot be correct since it is the ratio of the circumference of the regular hexagon to the diameter).. He made the sea cast, ten cubits²⁰¹1K. 7:23.. It is impossible to say “circular” since already it was said “square”²⁰²The verse notes that the “sea” at the top was circular, diameter 10 and circumference 30. But in v. 24 it says that below it was adorned by flower buds, 10 cubits at each side. This implies that the bottom was square.. It is impossible to say “square” since already it was said “circular”. If you said circular, it would turn out to contain 160 times the measure of purity. If you said square, it would turn out to contain 122 times the measure of purity. Therefore you have to say that the upper two cubits were circular, the lower three cubits were square and it turns out that it contained 150 times the measure of purity²⁰³The numbers are impossible; to make them approximately intelligible one has to switch the positions of “square” and “circular”. The height of the “sea” was 5 cubits. The “measure of purity” is the minimum size of a miqweh which is 3(cubits)³. If the “sea” were cubical, the outer volume would be 500(cubits)³ = 166⅔ miqwaot. Since the verse asserts that the walls were 1 hand-breadth wide (1/6 cubit) the actual inner volume was 4 5/6 (9⅔)² = 451.6481 (cubits)³ = 150.54 miqwaot. The fractional part should be disregarded. If the “sea” were a right circular cylinder, with the prescribed value of π=3 the outer volume would be 375(cubits)³ = 125 miqwaot; the inner volume 338.7361 (cubits)³ = 122.91 miqwaot. In v. 26 it is stated that the volume contained in the “sea” was 2’000 bat which is 6’000 seˋah or 150 miqwaot (Babli 14a, Pesaḥim 109b). This volume also is the sum of the volumes of a rectangular solid of edge legths 3,10,10 and a right circular cylinder of radius 5 and height 3, as stated in the text. The problem is that these are outer measures; the inner measures are consistently disregarded.. One verse says, it contained 2’000 bat²⁰⁴1K. 7:26., but another verse says, it contained a volume of 3’000 bat²⁰⁵2Chr. 4:5.. It is impossible to say 2’000 since already it says 3’000 and it is impossible to say 3’000 since already it says 2’000. Therefore you have 2’000 in fluid measure which are 3’000 in dry measure. From here the Sages learned that 40 seah in fluid measure are two kor in dry measure²⁰⁵2Chr. 4:5..