The haftorah of parshas Vayakhel, Shemos is from sefer Melachim. “Then he [King Solomon] made a metal tank, ten cubits from rim to rim, round; it was five cubits high, and thirty cubits in circumference” (Melachim I 7:23).
We are commanded to make a washing basin for the Cohamin to wash thier hands before they preform their servie in the Temple (Ki Sisa, Shemos 30:18) Shlomo Hamelech made a metal tank full of water used by the Kohanim (Priests) for ritual immersion (Divrei Hayamim II 4:6). Its diameter, according to the pasuk (verse), was 10 amahs (cubits) and its circumference was 30 amahs.
The formula for circumference is
C = D * π
Based on the values given in the pasuk for Circumference and Diameter of the vessel, can you solve for the value of Pi?
30 = 10 * π
30/10 = π
3 = π
Bonus question: What is the real value of Pi? (Answer: 3.14)
That’s a pretty close approximation of Pi in the Torah!