Theory:

Latitudes and Longitudes
  • Latitudes and Longitudes are horizontal and vertical imaginary line drawn to find the location and calculate time.
  • Ptolemy – first person to draw the lines of latitude and longitude on a map.
  • ‘Geographia’ a book by Ptolemy
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Latitudes
  • Imaginary lines
  • Runs horizontally on East - West direction on the Earth
  • They are called the lines or parallels of latitudes.
  • They are also called parallels, as they are parallel to the equators and never meet.
  • The 0° line of latitude which divides the Earth into two halves is known as the Equator.
  • These halves are known as Northern and Southern Hemisphere.
  • From the Equator, parallel lines are drawn towards the North and South poles at equal intervals.
Important!
The latitudinal extent: \(1° \)line of latitude \(= 111 km\).
  
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From the Equator toward North and South poles the length of the lines of latitudes decreases.
  • The \(90°\)North and\( 90°\)South (Poles) are not lines, they are found as points.
  • Northern latitudes – Lines of latitudes between the Equator and North Pole.
  • Southern latitudes – Lines of latitudes between the Equator and South Pole.
Total number of Northern latitudes (parallels in northern hemisphere) \(= 89\)
Total number of Southern latitudes (parallels in southern hemisphere) \(= 89\)
Equator \(= 1\)
At poles (as points) \(= 2\)
Total number of parallels found on earth \(= 181\) parallels
The Equator is the longest of all lines of latitude.  Hence, it is also known as ‘The Great Circle’.