GUATEMALA CITY - Torrential rains brought by the first tropical storm of the 2010 season pounded Central America and southern Mexico, triggering deadly landslides. The death toll stood at 15 Sunday but authorities said the number could rise.
Archimedes proved the formula for the area of a circle (A = Ï r 2, where r is the radius of the circle) and showed that the value of Ï lay between 3 + 1/7 (approximately 3.1429) and 3 + 10/71 (approximately 3.1408).
The symbol used by mathematicians to represent the ratio of a circle's circumference to its diameter is the lowercase Greek letter Ï, sometimes spelled out as pi, and derived from the first letter of the Greek word perimetros, meaning circumference. In English, Ï is pronounced as pie (/paÉª/, paÉª).