Question

work on pi by various mathematicians and their estimates for pi

Answer 1

Mathematicians have guessed the value of Pi since time immemorial. The Ancient Egyptians were the first to suggest a value for Pi and stated that it was 3.16045...
Archimedes is the first known person to have derived a correct value for Pi upto 3 digits.
Lui Hui, a Chinese mathematician was then successful in deriving the value to upto 5 digits.(3.14159)
Another Chinese mathematician Zu Chongzhi derived it up to 7 digits.
Madhava of Sangamagrama, an Indianderived it up to 10 digits.
William Jones, the mathematician who introduced the Greek symbol for Pi calculated it up to 100 places.
Today, the value can be calculated to more than 22 Trillion digits with the help of supercomputers!