Hello!
The answer is: Grids are used to find coordinates (Latitude and longitude coordinates).
Why?
Grids are used to find coordinates, it means to find latitude and longitude coordinates. Latitude and longitude help to find the object's positions on earth.
Latitude is a measurement on a map, going from the North to the South, at the opposite side, longitude is a measurement on a map, which goes from the East to the West of the prime meridian at Greenwich.
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