  Just now was glancing through a few pages of our president's book "ignited minds". In this passage he categorically states that Aryabhatta was THE first to give an approximation to Pi.
The passage goes this way "Aryabhatta, born in 476 AD in Kusumapura(now called Patna), was an astronomer and mathematician. He was reputed to be a repository of all the mathematical knowledge known at that point of time. He was only twenty-three years old when he wrote Aryabhatiyam in two parts. The text covers arithmetic, algebra and trignometry and of course, astronomy. He gave a formula for the areas of a triangle and a circle and attempted to give the volumes of a sphere and a pyramid.
He was the first to give an approximation to pi as the ratio of a circle's circumference and diameter, arriving at the value of 3.1416. to celebrate this great astronomer, India named its first satellite launched in 1975 Aryabhata" 
