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).
Now let us put the center at (a,b) So the circle is all the points (x,y) that are r away from the center (a,b). Now lets work out where the points are (using a right-angled triangle and Pythagoras): It is the same idea as before, but we need to subtract a and b: (xâa)2 + (yâb)2 = r2.