Definition:Pi/Historical Note

Historical Note on $\pi$ (Pi)
Every ancient society that considered circles was aware of $\pi$, although in general only as a rough approximation.

In the Old Testament, the implication is that $\pi = 3$:
 * And he made a molten sea, ten cubits from the one brim to the other: it was round all about, and his height was five cubits: and a line of thirty cubits did compass it round about.
 * -- $\text I$ Kings $7 : 23$

The Egyptian scribe in the  used the approximation that the area of a circle equals the area of a square whose side is $\dfrac 8 9$ that of the diameter of the circle, leading to a value of $\pi$ of $\left({\dfrac {16} 9}\right)^2 = 3 \cdotp 16049 \ldots$

Ancient as is the concept of $\pi$ (pi), the symbol $\pi$ that is used for it appears to date back only as far as.