How calculate the Lat/Lon 5km east or north of my current location?

Question

I want to calculate the coordinates in Lat/Lon of the points B and C. And A is my current location, for example Lat: 48.23490 Lon: 13.177660.

I retrieve my current location. But now I don't know how to calculate the point B and C.

Refer to my picture please.

This is what I found >>This<<

Can anyone help me how to achieve this? But I dont know what I should do with it.

Answer 1

Using the method from here and assuming east is positive, we can do:

dy = 5.0 / 110.54;
dx = 5.0 / (111.320*Math.cos(Alat/180*Math.PI));
Blon = Alon + dx;
Blat = Alat + dy;
Clon = Alon - dx;
Clat = Alat - dy;