using System;

public class Program

{

    public static void Main()

    {

        double[]  coordinate= GetSquareAroundCoordinate(45.4654219,9.18951,1);

        Console.WriteLine(coordinate[0].ToString() +"___" + coordinate[1].ToString() +"___" +coordinate[2].ToString() +"___" +coordinate[3].ToString());

    }

     public static double[] GetSquareAroundCoordinate(double lat, double lng, double radiusKm)

        {

            double oneYDegEqKm = 111.111d;

            double oneXDegEqKm = 111.111d * Math.Cos(Math.PI / 180 * lat);

​

            double yChange = radiusKm / oneYDegEqKm;

            double xChange = radiusKm / oneXDegEqKm;

            double neLat = lat + yChange;

            double swLat = lat - yChange;

            double neLng = lng + xChange;

            double swLng = lng - xChange;

​

            return new double[] { neLat, swLng, swLat, neLng };

        }

}