Circles on the Earth’s surface with their centers on
the line joining the north and south poles are called circles
of latitude. Lines of Latitude are the horizontal lines
running east-to-west on maps. All these circles are in planes
parallel to the plane containing the equator. They are sometimes
referred to as parallels of latitudes.
is said to be at latitude 52° north. Sydney, Australia, has
a latitude of about 34° south.