Imagine if you wrapped a rope tightly around the earth at the equator. how much longer would you have to make the rope if you wanted it to be exactly one foot above the surface all the way around?

Use the formula: 2(pi)(r + 1) - 2(pi)r

In your problem, you didn't give any measurements to use, so we can't determine an exact answer. However, the given formula above would work. 

The first term calculates the extended length of rope. The second term calculates the original length of rope. All you need to do is subtract them.

Online, you can find the radius of the Earth if you need an exact value. 3,959 miles