using System;

​

public struct Vector2

{

    float x;

    float y;

    float x1;

    float y1;

    public Vector2(float xx, float yy, float x1x, float y1y)

    {

        x = xx;

        y = yy;

        x1 = x1x;

        y1 = y1y;

    }

​

    public float Get_x()

    {

        float get_x = x;

        return get_x;

    }

​

    public float Get_y()

    {

        float get_y = y;

        return get_y;

    }

​

    public float Get_x1()

    {

        float get_x1 = x1;

        return get_x1;

    }

​

    public float Get_y1()

    {

        float get_y1 = y1;

        return get_y1;

    }

​

    public float length_vec()

    {

        float length = (float)Math.Sqrt(x * x + y * y);

        return length;

    }

​

    public float length_vec1()

    {

        float length = (float)Math.Sqrt(x1 * x1 + y1 * y1);

        return length;

    }

​

    public float normalx_vec()

    {

        float x_normal = y;

        return x_normal;

    }

​

    public float normaly_vec()

    {

        float y_normal = -x;

        return y_normal;

    }

​

    public float normalx1_vec()

    {

        float x1_normal = y1;

        return x1_normal;

    }

​

    public float normaly1_vec()

    {

        float y1_normal = -x1;

        return y1_normal;

    }

}

​

public class Program

{

    Vector2 vec1 = new Vector2(1, 3, 5, 1);

    static float dot_product(Vector2 vec)

    {

        float dotp = vec.Get_x() * vec.Get_y1() + vec.Get_y() * vec.Get_x1();

        return dotp;

    }

​

    static float KhoangCach(Vector2 vec)

    {

        float khoangCach = (float)Math.Sqrt((vec.Get_x1() - vec.Get_x()) * (vec.Get_x1() - vec.Get_x()) + (vec.Get_y1() - vec.Get_y()) * (vec.Get_y1() - vec.Get_y()));

        return khoangCach;

    }

}