How can I get the latitude and longitude of “x” meter from ref latitude and longitude?

Question

I have a distance in meters and ref latitude and longitude. Now I want latitude and longitude from the given ref point on x meters in four direction (south, north, east and west).

How can I get this value?

I need to write this in C#, but any pseudocode or logic guidance will be welcome.

Update:

I have a coordinates as references point from that I want to calculate distances of 5 meters in north direction keeping longitude as constant. So I want to calculate latitude at a distance of 5 meters from my reference point. Same I have to do for all 3 directions in east west direction I am keeping longitude as a constant.

Please let me know if any formula we can use for this.

Answer 1

How accurate does it have to be? You can often assume the earth is a sphere with a radius of 6360 km. In that case, one degree north or south is 10000/90 kilometers (that's how the meter was defined). East/West is only slightly harder, one degree east is 10000/90 km * cos(latitude).