Pi Trivia Questions and Answers

Pi is one of the most well-known mathematical constants, representing the ratio of a circle's circumference to its diameter. It's been studied for thousands of years and has many fascinating properties.

Test your knowledge of pi with these pi trivia questions and answers to find out how much you know about this day. Don't forget to play this with friends and family members.

For more quizzes, see our trivia quiz sitemap.

Pi Trivia Questions

1. What is Pi Day?

2. Who is credited with calculating the first few digits of pi?

3. What is the mathematical symbol for pi?

4. What is the value of pi to two decimal places?

5. What is the value of pi to five decimal places?

6. What is the formula for calculating the circumference of a circle using pi?

7. Who introduced the symbol π to represent pi?

8. What is the record for memorizing the most digits of pi?

9. What is the name of the irrational number that is approximately equal to pi?

10. Who is the first person known to have used the Greek letter π to represent pi?

11. What is the ratio of the circumference of a circle to its diameter?

12. Who calculated the first 100 digits of pi by hand?

13. What is the value of pi to 10 decimal places?

14. What is the area of a circle with a radius of 4 cm, using pi as 3.14?

15. Who wrote a poem called "The Raven" that contains a reference to pi?

16. What is the name of the famous book that features pi in its title and is about a boy who memorizes the digits of pi?

17. Who is the first person known to have used the Greek letter π to represent pi in writing?

18. What is the diameter of a circle with a circumference of 12π?

19. What is the name of the longest pi-related song ever recorded?

20. What is the relationship between the circumference and the diameter of a circle?

21. Who proved that pi is irrational?

22. In September, 1999, the value of Pi was calculated to a record number of decimal places. How many?

23. Pi is named after a letter of which alphabet

24. If you multiply Pi by the square of the radius of a circle, what do you get

25. The Greek letter Pi is also used in legal shorthand to represent what

26. What is the name given to the practice of memorizing large strings of pi digits through various mnemonic techniques?

27. In 2010-2011, how many days were needed to calculate the current record of 10 trillion decimal places for pi?

28. Which of these fractions is closest to Pi?

29. Was Albert Einstein was born on a Pi Day

30. Suppose you wanted to measure the size of the known universe with an error no larger than the size of a hydrogen atom. How many decimal places of pi would you need

Pi Trivia Answers

1. Pi Day is celebrated on March 14th (3/14) to honor the mathematical constant pi, which is approximately equal to 3.14.
2. Archimedes
3. π
4. 3.14
5. 3.14159
6. C = 2πr
7. William Jones
8. 70,000 digits
9. Ludolphine number or Leibniz's formula
10. William Oughtred
11. Pi (π)
12. John Machin
13. 3.141592654
14. 50.24 cm²
15. Edgar Allan Poe
16. Life of Pi by Yann Martel
17. Welsh mathematician William Jones
18. 6
19. Pi" by Hard 'n Phirm
20. The circumference is equal to pi times the diameter.
21. Johann Lambert
22. 206 billion
23. Greek
24. The circle's area
25. Plaintiff
26. Piphilology (a play on the words “pi” and “philology”)
27. 371 days
28. 22 over 7
29. Yes
30. 3