Pi(π)

π is a real irrational number.It has a great importance in Mathematics,Physics and in many fields.It is the ratio of perimeter to diameter of a circle.

History of Pi(π)

More than years ago human thought about the relation between perimeter and radius of a circle.IN Babylon they used the ratio 3.0.but a tablet in Babylon around 1900-1680 BC indicated the ratio between perimeter to radius of a circle 3.125 which closer to π .
The egyptians treated the ratio as 3.1605

Pi was first calculated by Greek Mathematician Archemedes.His algorithm was taking two polygon one is circumscribed and second is inscribed of a circle.The value of perimeter of the circle will lie between the perimeter of two polygons.And then taking the ratios.Then he showed that the value of Pi is between 3 1/7 and 3 10/71.

This is Archemedes polygon

Later a Chinese Mathematician Zhu Chongzhi(429-500 AD) calculated the ratio as 355/113

π was first used as the ratio of perimeter to radius in 18th century.First said William Jones.

Now with help of computer we got more accurate value of Pi.Mathmaticians have calculated Pi to milions of digit after decimal.