public class Circle extends AbstractShape {
	
	private double radius;
	
    public Circle( double rad ) {
        radius = rad;
    }
    
    public double area( ) {
        return Math.PI * radius * radius;
    }
    
    public double perimeter( ) {
        return 2 * Math.PI * radius;
    }
    
    public String toString( ) {
        return "Circle: " + radius;
    }
}