static void Main()
{
DistanceCalculator startpoint = new DistanceCalculator(0, 0, 0);
DistanceCalculator topoint = new DistanceCalculator(1, 2, 3);
Console.WriteLine(startpoint.Calcdistance(topoint)); //instance
Console.WriteLine(DistanceCalculator.Calcdistance(startpoint, topoint)); //static
}