Question

“The degree of longitude decreases in length poleward”. Why?

Answer 1

The Equator is the longest parallel on the Earth. All other parallels become shorter polewards due to the spherical shape of the Earth. So the meridians near the poles have a narrow space. One degree of longitude is the longest at the equator (111 km) at 45° latitude it is 79 km, at 60° latitude it is 55 km and at poles, it is zero km.