Interface.java

interface Results
{
final static float pi = 3.14f;
float areaOf(float l, float b);
}
class Rectangle implements Results
{
public float areaOf(float l, float b)
{
return (l * b);
}
}
class Square implements Results
{
public float areaOf(float l, float b)
{
return (l * l);
}
}
class Circle implements Results
{
public float areaOf(float r, float b)
{
return (pi * r * r);
}
}
public class Inter
{
public static void main(String args[])
{
Rectangle rect = new Rectangle(); 
Square square = new Square(); 
Circle circle = new Circle();
System.out.println("\r\nArea of Rectangle: "+rect.areaOf(20.3f, 28.7f)); 
System.out.println("Are of square: "+square.areaOf(10.0f, 10.0f)); 
System.out.println("Area of Circle: "+circle.areaOf(5.2f, 0)); 
}
}