lines of longitude can be best be described as

Lines of longitude are imaginary lines that run from the North Pole to the South Pole and divide the Earth into halves, known as the Eastern Hemisphere and Western Hemisphere. These lines are also known as meridians. Longitude is the measure of a location's distance from the Prime Meridian, which is an imaginary line running from the North Pole to the South Pole and passing through the Royal Observatory in Greenwich, London. The Prime Meridian is used as a reference point to measure the longitude of other locations on Earth. Therefore, the best description of lines of longitude is that they are imaginary lines on the Earth's surface that join the North and South Pole and are used to measure the distance of a place east or west of the Prime Meridian.