In Archimedes' day, close approximations of pi had been known for over 1,000 years. An Egyptian document dated to 1650 B.C., for example, gives a value of 4 (8/9) 2, or 3.1605. Archimedes' value ...

For some, today (July 22) is Pi Approximation Day, but for some others, it is March 14. Pi is the ratio of the circumference of any circle to the diameter of that circle. Greek letter π was first ...

the area of both circular faces is 2 × π × 5² = 50π m². When using the approximation π = 3۰142, the area of both circular faces is 2 × 3۰142 × 5² = 157۰1 m². Image caption ...