Latitude and Longitude are angles, not just some numbers on the earth’s surface.

Image source : Google

While working on one of recent project, I started reading how the coordinate system works. That time I figured out that latitude and longitude are angles and I never thought of it that way.

Latitude

Latitude is basically the the angle between equatorial plan / equator(from centre) and any point P on the surface of earth.

Ranges from -90(south pole) to +90(north pole)

Longitude

A half circle running from pole to pole through Greenwich, England is taken as reference to calculate longitude and is called prime meridian.

Longitude is the angle between prime meridian and the reference plane running from one pole to another in form of half circle that passes through point P

Ranges from -180(west) to +180(east)

Precision

Decimal  Degrees    Distance(Precision)
places
-------------------------------
0 x.x 111 km
1 x.x 11.1 km
2 x.xx 1.11 km
3 x.xxx 111 m
4 x.xxxx 11.1 m
5 x.xxxxx 1.11 m
6 x.xxxxxx 0.111 m
7 x.xxxxxxx 1.11 cm
8 x.xxxxxxxx 1.11 mm

In case you are interested in the project I have been working on

It is an app to find discounts in nearby restaurants, using your credit or debit card. In my case I have settled down to using 2 decimal places to fetch data from my application backend, Its really helpful with caching and displaying correct results to the user :)