The meridian used as a reference line for longitudinal measurements, from which the longitude grid is drawn, is called what?

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Multiple Choice

The meridian used as a reference line for longitudinal measurements, from which the longitude grid is drawn, is called what?

Longitudes are measured east or west from a fixed reference line that runs from the North to the South Pole. This baseline is the Prime Meridian, defined as 0° longitude and passing through Greenwich. The global longitude grid is drawn from this line, which is why every longitude value is measured relative to it. The Central Meridian, by contrast, is a projection-specific line used to center a particular map projection and is not the universal baseline for longitude. The Equator is the reference for latitude, and the Anti-Meridian is the 180° line opposite the Prime Meridian. So, the reference meridian for longitude is the Prime Meridian.

Longitudes are measured east or west from a fixed reference line that runs from the North to the South Pole. This baseline is the Prime Meridian, defined as 0° longitude and passing through Greenwich. The global longitude grid is drawn from this line, which is why every longitude value is measured relative to it. The Central Meridian, by contrast, is a projection-specific line used to center a particular map projection and is not the universal baseline for longitude. The Equator is the reference for latitude, and the Anti-Meridian is the 180° line opposite the Prime Meridian. So, the reference meridian for longitude is the Prime Meridian.

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