Omar drives a car five miles north then five miles west then five miles south How many miles is he likely to be from his starting point?

Omar drives a car five miles north then five miles west then five miles south How many miles is he likely to be from his starting point?
The obvious answer is 5 miles.The not-so-obvious part is it depends on where he is when he starts. If he is on the equator, he is five miles from his point of origin. If his starting point was the south pole, and he drives five miles north, then west, then south, he will arrive back at his starting point. Before you disagree, consider that he is driving on a sphere not a flat plain.