Earth's Circumference?

Question

In moving from 20 degrees to 50 degrees north latitude along a line of longitude I moved 2,000 miles. The earth's circumference is ____________miles.

Answer 1

50° – 20° = 30°
circumference = 360°

30° ———— 2,000 miles
360° ———— x

x = 2,000 miles * 360°/30° = 24,000 miles
you are not in the surface. You are a mole.

Answer 2

Since 30 degrees is 1/12th of the circumference of a circle (or sphere) multiply 2,000 miles by 12 and you get 24,000 miles. Of course, that is a bit too small, so you probably traveled a bit more than 2,000 miles.

Answer 3

You moved 30 degrees. The whole circumference is 360 degrees.

So if 30 degrees is 2,000 miles, then ...
... 60 degrees is 4,000 miles, and
... 300 degrees is 20,000 miles, then
... 360 degrees is _______ miles.