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 radius r is the distance from the center to a point on the circle. The diameter is. always twice the radius. It was discovered long ago that the ratio of the circumference of a circle to its diameter. always stays the same. The ratio has a special name. It is named by the Greek letter p (pi).