class DvouDObrazec { //dedeni-dvourozmerne obrazce
  private double width;  // !!privatni 
  private double height; // !!privatni   
 
  // Metody pro pristup z potomka 
  double getWidth() { return width; } 
  double getHeight() { return height; } 
  void setWidth(double w) { width = w; } 
  void setHeight(double h) { height = h; } 
 
  void showDim() { 
    System.out.println("sirka a vyska jsou " + 
                       width + " and " + height); 
  } 
} 
 
// Podtrida trojuhelniky
class Trojuhelnik extends DvouDObrazec { 
  String style; 
   
  double area() { 
    return getWidth() * getHeight() / 2;  
  } 
 
  void showStyle() { 
    System.out.println("Trojuhelnik je " + style); 
  } 
} 
 
class Obrazce { 
  public static void main(String args[]) { 
    Trojuhelnik t1 = new Trojuhelnik(); 
    Trojuhelnik t2 = new Trojuhelnik(); 
 
    t1.setWidth(20.0); 
    t1.setHeight(2.0); 
    t1.style = "placaty"; 
 
    t2.setWidth(5.0); 
    t2.setHeight(15.0); 
    t2.style = "hubeny"; 
 
    System.out.println("informace pro t1: "); 
    t1.showStyle(); 
    t1.showDim(); 
    System.out.println("plocha = " + t1.area()); 
 
    System.out.println(); 
 
    System.out.println("informace pro t2: "); 
    t2.showStyle(); 
    t2.showDim(); 
    System.out.println("plocha =" + t2.area()); 
  } 
}