AI Tutor
Imagine being stranded in the middle of the ocean with nothing around you except open water for a thousand miles. How would a rescue helicopter know the exact spot to find you?
They use an invisible grid drawn over the entire planet made of two sets of lines called latitude and longitude.

The Horizontal Lines: Latitude

Lines of latitude run horizontally around the Earth like belt loops, measuring distance north or south of the Equator.
The Equator sits at 0∘0^\circ, while the North Pole is at 90∘ N90^\circ\text{ N} and the South Pole is at 90∘ S90^\circ\text{ S}.
Lines around the middle give us the north-south position — but how do we pinpoint how far east or west you are?

The Vertical Lines: Longitude

Lines of longitude run vertically from the North Pole down to the South Pole, looking like orange wedges.
The starting line is the Prime Meridian at 0∘0^\circ (running through Greenwich, England), measuring up to 180∘ E180^\circ\text{ E} to the east and 180∘ W180^\circ\text{ W} to the west.
When a latitude line crosses a longitude line, they create an exact address on Earth called a coordinate pair.

Pinpointing Locations with Coordinates