abstrct.java

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/**
 *
 * @author g1.test1
 */
abstract class l
{
 double dim1,dim2;
 l(int x,int y)
 {
 dim1=x;
 dim2=y;
 }
 abstract double area();
}
class rec extends l
{
 rec(int x,int y)
 {
 super(x,y);
 }
 double area()
 {
 return (dim1*dim2);
 }
}
class trin extends l
{
 trin (int x,int y)
 {
 super(x,y);
 } 
 double area()
 {
 return (dim1/2*dim2);
 }
}
 public class abstrct {
 public static void main(String args[])
 {
 // a obj=new a(); cannot be made as abstract

rec obj1=new rec(10,20);
trin obj2=new trin(20,30);
l ref;
ref=obj1;
ref=obj2;
System.out.println(obj1.area());

System.out.println(obj2.area());
 }
 }