1. Facts on Pi Ashley Martin Geometry - Mrs. Smith 3-13-09

2. Definition of Pi • A transcendental number, approximately 3.14159, represented by the symbol 3, that expresses the ratio of the circumference to the diameter of a circle and appears as a constant in many mathematical expressions.

3. Facts • The fraction 22/7 is a well used number for Pi. • There is no zero in the first 31 digits of Pi.

4. Continued • The Babylonians found the first known value for Pi in around 2000BC. (25/8). • Pi is irrational

5. Continued • Pi is the 16th letter of the Greek alphabet. • Pi is the ratio of the circumference of a circle to its diameter.

6. More Facts.. • Some fractions that can be used for Pi • 25/8 • 22/7 • 333/106 • 355/113 • 104348/33215 • 837393900/266550757

7. Cont. • Π - the symbol used for Pi • Pi is a transcendental number. (Transcendental means= Not capable of being determined by any combination of a finite number of equations with rational integral coefficients.)

8. Cont.. • The sequence of digits in Pi so far passed all known tests for randomness. • For a circle to equal Pi, the diameter must be 1.

9. Cont. • All the digits of Pi can never be fully known. • Pi day is celebrated on March 14th at 1:59.

10. Cont. • The first person to use the Greek letter Pi was Welshman William Jones in 1706. He used it as an abbreviation for the periphery of a circle with unit diameter. • The area of a circle is Π r2. • The circumference is Π d

11. Cont. • Pi is used in many different equations. • Simon Plouffe was listed in the 1975 Guinness Book of World Records for reciting 4096 digits of Pi from memory.