# Antarctic Walk Puzzle

The key is that if you start at any point on a sphere and draw a straight line in any direction, you will draw the largest possible circle you can on the sphere.

What makes this puzzle tricky is that I gave you much more information than you needed to solve it. I could have set it up in many ways and the answer would have been the same:

“You start under the Eiffel Tower, walk 4.5 miles east, turn 70 degrees to your right, and then walk in a straight line.”

None of these details about starting point, direction, etc. matter. All that matters is that you are walking in a straight line on a sphere!