### 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 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 $$= 111 km$$. 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’.