Instruction:
Suppose you started at 0 degrees N, 0 degrees E on the earth. You started traveling due north, continuing straight for 2439 miles, turned 60 degrees counter-clockwise, traveled another 4878 miles, turned 60 degrees counter-clockwise traveled another 4878 miles, turned 60 degrees once again, and traveled another 4878 miles. At this point where would you be? Please explain the mathematics of how you came to your conclusion.

Response:
You would be approximately 35 degrees S, 0 degrees E, or 2439 miles south of your starting position, assuming the earth is a sphere with a circumference of 24,901 miles. After traveling 2439 miles north, you would be at 35 degrees N, 0 degrees E. After turning 60 degrees counter clockwise and traveling 4878 miles, you would be at 35 degrees N, 90 degrees W. Turning 60 degrees counter-clockwise and traveling another 4878 miles, you would arrive at 35 degrees S, 90 degrees W. Finally turning 60 degrees counter-clockwise and traveling 2439 miles you would arrive at 35 degrees S, 0 degrees W. If you returned to your starting position, you will have traced out a spherical square.