Interesting Math History

Question :
How do you explain pi (p) in a simple way ?

Answer :
Many practical problems are concerned with the measurements of a circle. And the basic to the measurements is the fact that the ratio of the circumference to its diameter is a constant. No matter what the size of the circle the ratio remains the same.
In mathematics, this ratio is represented by the Greek letter p (pi).
However this constant is not an integer and much effort has been spent to find the value of this ratio. It has been evaluated to a large number of decimal points by electronic calculators.

The story of the accuracy to which the value of p is known is an interesting one.

In the Bible, the value of p is used as 3 Archimedes had declared the value of p as less than 3 1/7 but greater than 3 10/71. The value generally used today 3.1416 was known at the time of Ptolemy (A.D. 150).

In 1949, with the use of the Computer Eniac, a group of mathematicians calculated 2037 decimals of p in 70 hours.

And recently Daniel Shanks and John Wrench have published p to 100,000 decimals. It took them 8 hours and 43 minuts on an IBM 7090 system to compute this result.

However for practical use the approximation of p 3.1416 is sufficient.