Question

Which way do lines of longitude run and what do they measure?

Answer 1

what do you mean measure?

Answer 2

They go north and south from the North Pole to the South Pole.

They don't really measure anything, per say. They are used to be able to identify points on the Earth's surface. Longitude changes as you go east and west. However, because the Earth is a sphere, longitude lines are further apart at the equator than they are anywhere else.