Java program to find area of circle and rectangle using interface

Let’s learn java program to find area of circle and rectangle using interface.

Java program to find area of circle and rectangle using interface

We can use interface to find area of circle and rectangle. Here’s the java program.

interface FindArea
{    
   double pi = 3.14159265359;    
   double calculate(double a, double b);    
}
class Rectangle implements FindArea    
{    
   public double calculate(double a, double b)    
   {    
      return(a * b);    
   }
}
class Circle implements FindArea    
{    
   public double calculate(double a, double b)    
   {    
      return(pi * a * a);    
   }    
}
public class FindAreaUsingInterface 
{
   public static void main(String[] args) 
   {
      Rectangle rect = new Rectangle();    
      Circle cir = new Circle();    
      FindArea area;
      area = rect;    
      System.out.println("Area of rectangle is: " + area.calculate(50, 30));      
      area = cir;    
      System.out.println("Area of circle is: " + area.calculate(10, 10));
   }
}

Output:

Area of rectangle is: 1500.0
Area of circle is: 314.15926535899996