Class

Basic Sample

private static void Main(string[] args)
{
    var p = new Point(0, 0);
    var q = new Point(10, 0);
    Console.WriteLine(p.DistanceFrom(q));
}

public class Point
{
    int x;
    int y;

    public Point(int x,int y)
    {
        this.x = x;
        this.y = y;
    }

    public double DistanceFrom(Point x)
    {
        return Math.Sqrt((this.x - x.x)*(this.x - x.x) + (this.y - x.y)*(this.y - x.y));
    }
}