Question

Why are lines of longitude known as meredians​

Answer 1

Answer:

Longitudes are known as meridians because in Geographical sense, meridians are great circles which are not parallel to each other but intersect each other at the North and the South Poles.

Answer 2

Longitude is measured by imaginary lines that run around the Earth vertically (up and down) and meet at the North and South Poles. These lines are known as meridians. ... The meridian that runs through Greenwich, England, is internationally accepted as the line of 0 degrees longitude, or prime meridian.