abstract class Figura{

  protected double podst;
  public Figura(double p) {

    podst=p; }
  public double pole() {

    return wysokosc()*podstawa(); }
  public final double podstawa(){ 

     return podst; }
  public abstract double wysokosc();

}

class Kwadrat extends Figura {

  public Kwadrat(double a) {super(a);}
  public double wysokosc() { 

    return podst; } 
}

class Prostokat extends Figura {
  protected double b;

  public Prostokat(double a, double b){
    super(a); this.b=b;}

  public double wysokosc()
  { return b; }

}

class Romb extends Figura {
  protected double alpha;

  public Romb(double a, double d) {
    super(a); alpha=d; }

  public double wysokosc()  { 
    return Math.sin(alpha)*podstawa(); }

}

public class Figury {

 public static void main(String args[]){
    Figura[] figury = new Figura[3];

    figury[0] = new Kwadrat(1);
    figury[1] = new Prostokat(1,1);

    figury[2] = new Romb(1, Math.PI/2);

    double d=0;

    for (Figura f: figury) 
      d += f.pole();

   
   System.out.println("Pole figur: "+d);

  }
}