Java program to find the circumference and area of the circle using interface.

import java.lang.*;
interface Circle
{
    final static float pi = 3.14f;
    public float compute(float r);
}


class  Area implements Circle
{
    public float compute(float r)
    {
        return ( pi * r * r);
    }
}

class Circumference implements Circle
{
    public float compute(float r)
    {
        return(2 * pi * r);
    }
}

class InterTest
{
    public static void main(String args[])
    {
            Area obArea= new Area();
            Circumference obCircum= new Circumference();
            Circle InObj;
            InObj=obArea;
            System.out.println("Area of Cirle=" +InObj.compute(5));
            InObj=obCircum;
            System.out.format("Circumference of
            Circle="+InObj.compute(10));
    }
}