How to add 1 kilometer to a Google Maps coordinate?

Question

How could you add 1 km (or 1,000 m) to a google maps coordinate to determine an area?

Example:

Radius formed by points A and B:

Point A = Latitude:-22.91009, Longetude: -43.107499.

Point B = Latitude(A)+VALUE, Longetude(B)+VALUE.

But the distance from A to B would be in kilometers or meters.

Answer 1

Assuming you calculated the radius by Pythagoras' theorem, it would not be in kilometers or meters, but in degrees. In this case you would have to make the difference between the latitudes of A and B and the difference between the longitudes of A and B. If the latitudinal distance between A and B were 10°and the longitudinal distance was 30°, by Pythagoras' theorem we would have:

10 2 + 30 2 = X 2 => 10 2 + 30 2 = 31,62

Whereas 1° of latitude are about 110 km and 1° of longitude varies from 110 km at the equator to 0 km at the poles *1 and supposing you were at the equator, the radius would be 3478 km.