The radius of the earth is 3963 mi. what is the surface area of the earth in square meters? (1 mi = 1609 m.)'

You can think of the earth as almost a sphere(although its not sphere, but a little bit flat at the poles) for this case and then use the formula for finding the surface area of the sphere.

The surface area of the earth in square meters is 510940227330702.3 square meters or

How to find the surface area of a sphere with radius r units?

The surface area of a sphere with radius of r units is

Since the radius of the earth is approx 3963 miles, and we have

1 mi = 1609 m approximately, thus,

Thus, surface area of the earth would be approximately

(here we made assumption that earth is perfect sphere with radius 3963 miles which isn't true, so this area is like hypothetical but it gives a rough idea of how big the surface area can be)

Thus,

The surface area of the earth in square meters is 510940227330702.3 square meters approx or

Learn  more about surface area of sphere here:

link

Surface Area of a Sphere = 4 • π • radius²

Surface Area of a Sphere = 4 * 3.14159 * 3,693*3,693

Surface Area = 171,383,146.70 square miles

1 square mile = 1,609 * 1,609 = 2,588,881 square meters

171,383,146.70 square miles * 2,588,881 = 4.437 x 10^14 square meters

This problem claims that both triangles are similar because they are the exact same right triangle except one of them is bigger in area than the other.

The sides on the bigger triangle that you do know are 68 and 32. You divide those numbers by their match on the smaller triangle to find the scale factor, or how much bigger one triangle is than the other. For example, 68/17=4. This means that each of the larger triangles sides are divisible by 4.

Therefore, the side missing the x value will be equal to 60 because 15*4=60. You would then write the equation 4x+12=60. Subtract twelve from both sides to isolate the variable, so you would get 4x=48. Divide each side by 4, and then you will get your answer of x=12.

You can check the answer by plugging twelve into your equation as x, and you will get 60.