Question

About 70% of Earth’s surface is covered by water. If the diameter of Earth is about 12,750 km, find the area not covered by water to the nearest 100,000 km2.

Answer 1

Earth diameter = 12,750 km
Earth radius = 6,375 km
Sphere Surface Area     =     4 • π • r²
Sphere Surface Area     =    4 * 3.14159 * 6375^2
Sphere Surface Area     =    4 * 3.14159 * 40,640,625
Earth's Entire Surface Area     =    510,704,724 square kilometers
Surface NOT covered by water =  510,704,724 * .3
Surface NOT covered by water =  153,211,417 square kilometers