Another shot in the dark:
If he's 5 meter away from the south pole, he'll be standing on the south pole when done. If you go north from the south pole you can go to whatever direction you wan't.
Macca decides he want's to create a triangle with one right angl. The distance from the flag (x) and the 3 m north are the short sides, whereas the 5 meter is the long side.
x^2=5^2-3^2
x^2=16
x=4
He's 5 meters away from the south pole.