Nigeria, a country located in West Africa, is situated between the longitudes of 3°E and 15°E. Longitude lines are imaginary vertical lines that run across the Earth's surface from the North Pole to the South Pole. These lines help in determining the east-west position of a particular location on earth. By being positioned between 3°E and 15°E, Nigeria stretches from slightly east of the Prime Meridian, which is 0°, to 15° eastward. This geographical positioning affects several aspects like climate and time zone, making it an important detail in understanding the country's location globally.