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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.

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  • Have you considered adding 2 more points? D and E ? – user1940676 Nov 27 '13 at 09:49
  • I'm not sure whether [Geographical Distance](http://en.wikipedia.org/wiki/Geographical_distance) can help you or not. I'm not an expert in this field also... – Andrew T. Nov 27 '13 at 09:52
  • Do you need an exact result or are approximate values enough? – Henry Nov 27 '13 at 09:52
  • I just need the points B and C. It doesn't have to be completly exact. –  Nov 27 '13 at 09:54
  • I added a link. please take a look at it. But this solution consider not enough explanation for me. I dont know what to do with it. –  Nov 27 '13 at 09:59

1 Answers1

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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;
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Henry
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  • OK it seems logical. I will test it. Do you know how exact it is? Or whats the variation? –  Nov 27 '13 at 10:07
  • The accuracy will vary depending on the location, I don't know how large the difference can be in the worst case. – Henry Nov 27 '13 at 10:10
  • it says that the `cos()` method is undefined for the type MyActivity. So I can't do it in an Activty? –  Nov 27 '13 at 10:15