Pi Day 2025

The first recorded use of π as a mathematical symbol comes from the Welsh mathematician William Jones in Synopsis Palmariorum Matheseos, in which he abbreviated the Greek περιϕέρεια, to its first letter: π.

What does the Greek word, περιϕέρεια, translate to?

Rounded to the nearest whole number, what it the area of a circle with radius 1?

During what century did mathematicians start using the symbol, $$\pi$$ , that we know as pi?

Over 40 centuries ago, who was very likely the first to use a value for pi to calculate the area of a circle?

What are the first 7 digits of Pi?

Which of the following is NOT another term for $$\pi$$ ?

Which of these circles is the biggest?

In the Star Trek episode “Wolf in the Fold,” this character foils the evil computer by commanding it to “compute to the last digit the value of pi.”

Imagine you encircled the entirety of Earth's equator with a single piece of rope. Suppose you want to uniformly raise the rope above earth's surface by one inch. How much more rope would you need to accomplish this?

(The radius of Earth's equator is approximately 250,826,270 inches)

Which of the following ratios is constant (never-changing), regardless of a circle's size?