great circles

LESSON 5: GREAT CIRCLES

Definition: These is imaginary lines running across the globe dividing the earth into two equal parts or halves at the center of the globe

Great circles are formed when longitudes in the west meets with the counterparts in the east E.g.

• longitudes 10° west and 170° east form a great circle
• longitude 160° west and longitude 20°

NB: The equator is the only latitude that forms a great circle that is because it is the only latitude that divides the earth into 2 equal parts. They others latitudes are not great circles because their lengths are different

IMPORTANCE OF GREAT CIRCLES

Great circles are important because they offer the shortest distance between two places on the earth surface. This is why pilots and ship captains follow them during their flights and navigations respectively.

NB: DIFFERENCES BETWEEN LATITUDES AND LONGITUDES

 LATITUDES LONGITUDES They are parallel to each other They meet at poles Length vary ,the equator been the longest Have equal length Are measured from 0° at the equator to 90° north and south Are measured from 0° at Greenwich meridian to180°east and 180° west Only the equator forms a great circle Longitudes in the west and their counter parts in the east make up great circles They divides the earth into biomes They divides the earth in many time zones They run from west to east They run from north pole to south pole