This is the formal definition of pi.
What is "the ratio of a circle's circumference to its diameter"?
This equality contains the additive identity, the multiplicative identity, the fundamental circle constant, Euler's number, and the imaginary unit.
What is "Euler's Identity?"
This is the area of a circle with radius z and thickness a.
What is a "pi zz a"?
This is the connection between Albert Einstein and Pi Day.
What is "a birthday on March 14"?
The world pi-recitation record according to Guinness as of 2025 was approximately this number.
What is 70,000?
Pi is a transcendental number because of this quality.
What is "it's not the root of a non-zero polynomial with integer rational coefficients"?
This formula describes the sum of internal angles of a regular convex polygon with n sides.
What is "S = (n-2)pi"
This term refers to 3.14% of sailors.
What are "pi-rates"?
This state actually legislated the value of pi as 9.2376.
What is Indiana?
This mathematician showed that one way to calculate the value of pi is to find the perimeter of polygons inscribing and circumscribing a circle and increase the number of sides of the polygon.
Who is Archimedes?
German mathematician Johann Lambert famous is famous for proving this about pi in 1768.
Pi is irrational.
The maximum height of this famous curve is equal to 1/sqrt(2*pi).
What is the "standard normal distribution"?
This is the most mathematically inclined reptile out there.
What is a "pi-thon"?
This was the year the first 100 digits of pi were first calculated.
What is 1706?
For the first time in 1949, a digital computer (ENIAC) took 70 hours to calculate pi to this many decimal places.
What is 2037?
This formula proves that pi is an alternating series.
What is the Madhava-Liebniz formula?
Pi makes a surprising appearance in this problem that deals with the probability that a thrown needle will lie across a line between two strips.
What is "Buffon's needle problem"?
This 1967 pop tune is the perfect song for a mathematician at the beach.
What is "Good Pi-brations"?
You need this many digits of Pi to be able to measure the circumference of the observable universe to the width of 1 hydrogen atom in accuracy.
Working in isolation in India, this mathematician produced many innovative and rapidly-converging series for computing pi.
Who is Srinivasa Ramanujan?
For many years, it has been conjectured but unproven that pi is normal in base 10. This is what normal means.
What is "every sequence of n digits appears with a frequency of 1/10^n"?
This is the probability that if you pick any two integers at random, they will be relatively prime.
What is 6/pi^2?
This describes the religious fervor with which all mathematicians venerate this day.
What is "pi-ety"?
This refers to the sequence of six 9s at the 762nd decimal place of pi.
What is the "Feynman Point"?
A type of this approximation method is to have a computer pick two random numbers, x and y, each between -1 and 1. If it does so N times, and if, for M of those times x^2 + y^2 < 1, then pi is approximately equal to 4*M/N.
What is a "Monte Carlo simulation"?