Close! Very close. [ So he's familiar with something like Cartesian coordinates, that's a good start. ] Of course they won't be squares, since the surface is curved, but -

[ Qubit taps a couple of keys on his watch, and the globe redraws itself more abstractly, a plain blue sphere with the continents outlined in green, and a few more elements that get drawn in as he mentions them, sometimes poking the globe and sometimes his watch. ]

Rotational axis, north pole to south. Equator - an orthogonal plane bisecting the axis. They intersect at the center of the planet, we'll make that the origin. [ Represented by another orange dot. ] Lines of latitude - indicating the angle of deflection north or south of the equator. So here's thirty degrees, sixty, and the poles at ninety. Lines of longitude - the angle east or west of an arbitrary Prime Meridian, here. Thirty, sixty, ninety, and they meet at one-eighty. And I should clarify, these are just the conventions in use on my world, yours may be different.

[ Which is a long and excessively pedantic way of saying "yeah, you divide it into segments." They've got a very nice wire-frame Earth now. Good job. ]

However - [ he holds up two fingers. ] - that still only gives us two-dimensional coordinates. What about elevation?