Question

The area of the surface of a sphere is described by the formula S=4(3.14)r^2. The earth has a radius of 3960 miles and dry land forms 29.2% of the earth’s surface. What is the area of the dry land on earth?

Answer 1

Answer: $57,512,581.63miles^2$

Step-by-step explanation:

Substitute the value of the radius of the Earth into the formula given in the problem, where r is the radius, to obtain the surface area of the Earth:

$S=4(3.14)r^2\\S=4(3.14)(3,960miles)^2\\S=196,960,896miles^2$

The problem says that the dry land forms 29.2% of the Earth’s surface, therefore, multiply the surface area by $\frac{29.2}{100}=0.292$

Threfore, the area of dry land is the following:

$S_{land}=(0.292)(196,960,896miles^2)=57,512,581.63miles^2$