[lee martell]

I’m not trying to Rain Cloud your post, but my only question about Pi is this: What is it used for in today’s world, except as an Open Set measurement of long ‘numbers’?
**P.S., I’m not that good at math, and have only rarely enjoyed it.

[Reno89519]

At pizza sizes, not important, but at orbits, say for the International Space Station, which averages around 248 miles, a few extra decimal places makes an incredible difference.

For example, if you know the speed (around 17,500 mph) and altitude, you could calculate when it will be over a specific point as it orbits the Earth.

Or, what about a pinpoint laser to bounce off Mars, like a shotgun, you could calculate how much to lead that laser.

[NorthMountain]

For one example, "pi" is an integral (ha ha) part of Gauss's Law, and of Ampere's Law, which partly describe electromagnetism. Designing the computer you're typing on, and the communications systems that form the internet by which you pose your question and I answer it, depend on a proper understanding of that field (ha ha). Pi is also involved in the Schroedinger equation, fundamental to quantum mechanics. Design of solid-state devices, among many other things, is at least partly dependent upon understanding that field.

So, aside from the area and circumference of circles, and the volume and surface area of spheres ... pi may be hidden from your view, but it is fundamental to the modern world you may well take for granted.

And, by the way, e^iπ + 1 = 0

[cymbeline]

“What is it used for in today’s world”

It’s how you figure the circumference or area of a circle given its diameter.