Sextant is a measuring instrument used to measure the angle of elevation of a celestial object above the horizon academickids.com/encyclopedia/index.php/Sex... Longitude
Longitude describes the location of a place on Earth east or west of a north-south line called the Prime Meridian academickids.com/encyclopedia/index.php/Lon... Equator
The equator is an imaginary line drawn around a planet, halfway between the poles. The equator divides the surface into the Northern Hemisphere and the Southern Hemisphere... academickids.com/encyclopedia/index.php/Equ... Latitude
Latitude gives the location of a place on Earth north or south of the Equator.. academickids.com/encyclopedia/index.php/Lat... Navigation academickids.com/encyclopedia/index.php/Nav...