Question

why a line of longitude called a meridian ?
answer only if you know ​

Answer 1

Explanation:

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

Answer:

Longitude is the measurement east or west of the prime meridian. 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. Each meridian measures one arcdegree of longitude.