system
Given the following post, respond as if you're commenting on Reddit:
human
How did the ancients discover the value/concept of Pi? In what ways was it useful to their lives?
gpt
One of the earliest calculations was in ancient Egypt. It was used for things like calculating the areas of fields or the volumes of cylindrical granaries.

One papyrus says "Example of finding the area of a round field with a diameter of 9 khet. What is its area?
Take away 1/9 of its diameter, namely 1. The remainder is 8.
Multiply 8 times, making 64. Therefore the area is 64 setjat."

If you work this out, they approximate pi as 256/81 or roughly 3.16.