The reason as to why longitude lines converge while latitude lines do not is;
Explanation:
That latitude lines are parallel to the equator, which means they cannot meet with the equator. They measure the distance from the equator to the north and south, they therefore do not converge.
On the other hand, longitudes measure distance from the equator to the east and west, they meet at the north and south pole thereby converging.
The longitudes usually divert at the poles, which are the actual distance between two different meridians which is parallel. While moving closer to the poles the range that corresponds to one of latitude degree becomes more excellent than that corresponding to the longitude
Therefore it is not easy to calculate the lengths of the latitudes using through the use of graticule because the lines are concentric and they become small as you move closer to the poles. They form to construct a single point where the meridian starts.
