已知一点的经纬度和该点到另一点的距离,求另一点的经纬度

以下是将距离换算成经纬度，有误差。

//将相对于起点的距离转换为经纬度,distance代表到点的距离，angle代表方位角度
private string ConvertDistanceToLogLat(float distance, string logLatPtStr, double angle)
{
string logLat = null;
string[] temp_Arrary = logLatPtStr.Split(',');
double lng1 = ConvertLongiToDouble(temp_Arrary[0].Replace("(",""));
double lat1 = ConvertLongiToDouble(temp_Arrary[1].Replace(")",""));
double lon = lng1 + (distance * Math.Sin(angle* Math.PI / 180)) / (111 * Math.Cos(lat1 * Math.PI / 180));//将距离转换成经度的计算公式
double lat = lat1 + (distance * Math.Cos(angle* Math.PI / 180)) / 111;//将距离转换成纬度的计算公式
string logStr = ConvertLogLatToString(lon);
string latStr = ConvertLogLatToString(lat);
logLat = "(" + logStr + "," + latStr + ")";
return logLat;
}


//将double值转换成度分秒字符串
private string ConvertLogLatToString(double lon)
{
string resut = null;

string temp = lon.ToString();
string[] du = temp.Split('.');
resut += du[0] + "°";
double fen = (lon - Convert.ToDouble(du[0])) * 60;
string[] fen_Arrary = fen.ToString().Split('.');
resut += fen_Arrary[0] + "′";
if (fen_Arrary.Length > 1)
{
double second = Math.Round((fen - Convert.ToDouble(fen_Arrary[0])) * 60, 0);
resut += second.ToString() + "″";
}
return resut;
}