public class Geometry{
public abstact double area(){
return 0;
}
}
public class Circle extends Geometry{ private double r; public Circle(double r){ this.r=r; } public double area(){ double t; t=Math.PI*r*r; return t; } }
public class Triangle extends Geometry{ private double a; private double b; private double c; public Triangle(double a,double b,double c){ this.a=a; this.b=b; this.c=c; } public double area(){ double p; double t; p=(a+b+c)/2; t=Math.sqrt(p*(p-a)*(p-b)*(p-c)); return t; } }
public class Example{ public static void main(String ages[]){ Geometry g1; g1=new Circle(2); Geometry g2; g2=new Triangle(3,4,5); System.out.println(g1.area()); System.out.println(g2.area()); } }
