Lets pretend that the Earth is a perfect sphere. Surface area of a sphere = 4(pi)(radius)^2. The radius of earth is 6378.1 km. Plug that into your equation and you'll get your answer.
No.The simple answer is that the Earth is a sphere, a really big ball. This means that everywhere there is a tiny, tiny (convex) curve to the surface of the Earth. The curve is so weak that it's not...
The total surface area of the Earth is 510,072,000 square kilometers, but only 29.2% of that, or 148,940,000 square kilometers is land. The rest is covered by water.