[MosesKnows]

One can also do this calculation in the head but most will not realize it until they do the math.

What is the length of rope needed to encircle the earth at its largest diameter assuming the earth is a perfectly flat sphere?

After you have an answer you feel confident with calculate how much additional rope is required to raise the rope exactly one foot off the earth’s entire surface?

[justlurking]

What is the length of rope needed to encircle the earth at its largest diameter assuming the earth is a perfectly flat sphere?

It depends on whether you are raising the rope a foot above the surface at a single point, or the entire rope.

For the former, it's exactly 2 feet (1 up and 1 down).

For the latter, you are simply increasing the diameter by 2 feet, so the circumference will increase by 2 * Pi, or about 6 feet, 3 inches.

This is the correct answer for a sphere or circle of any size.