class Box
{
// Instance Variables
double length ,ipsos ;
double width ,mikos ;
double height ,platos;
// Constructors
 public Box ( double side )
{
width = side ;
height = side ;
length = side ;
}
public Box ( double x , double y , double z)
{
    platos = y ;
ipsos = z;
mikos = x ;

}

// Methods
double calculate(double praksi)
{
return 2 * ( width * height +
width * length +
height * length ) ;
}
double volume(double emvadon)
{
return platos*ipsos*mikos ;
}

@Override
public String toString() {
    return "Volume: " + volume(1) + "\n Calculate: " + calculate(1);
}
public class Cube extends Box {
    public Cube(double side) {
        super(side, side, side);
        if (side<0) { System.out.println("lathos timi");} 
    }

public void calculate2(double z )
{super.calculate( z  );}
public void volume2(double y)
{super.volume( y );}
@Override
public String toString() {
    return "Volume: " + super.volume(1) + "\n Calculate: " + super.calculate(1);
}


}
public class Spirtokouto extends Box {
    public Spirtokouto(double side) {     
        double weight;
        super(side, side, side,side);

    }

}

}

只有最后一部分（我的意思是我仅对此有问题）

当我编译它时，我没有合适的构造函数错误。为什么是这样？？顺便说一下，Spirtokouto类的目的是要增加一个计数值（权重）。我可以将一个班级扩展到>
1个班级吗？