Answer
The lines that run north to south but measure distance east to west are called meridians or lines of longitude.
Step-by-step explanation
Meridians are imaginary lines that connect the north and south poles of the Earth. They are used to measure the angular distance of a location east or west of the prime meridian, which is the meridian that passes through Greenwich, England. The prime meridian is assigned a value of 0 degrees longitude, and the other meridians are numbered up to 180 degrees east or west.
The distance between two meridians varies depending on the latitude, because the Earth is not a perfect sphere but an oblate spheroid, meaning it is slightly flattened at the poles and bulging at the equator. The distance is greatest at the equator, where it is about 111 kilometers (69 miles) per degree of longitude, and smallest at the poles, where it is zero.