Polymorphism

[Monzers]

i have the SAME problem <<mod edit: as this >> and im habing a lot of trouble with area of circle and writing assigning it a radius value so that the output will only tell me its radius and area. i have this so far: package Project4;

public class Circle extends TwoDimensionalShape{
	// declare instance variables
    Circle (double diameter) {
    	this.diameter = diameter;
            double radius = diameter / 2.0;
            this.area = PI * radius * radius;
        }

        private static final double PI = Math.PI;
        private double diameter;
        private double area; 
        
        // area of circle
        public double area () {
        	return area;
        }
        public static void main(String[] args)
    	{//declare local variables
    		Circle radius = new ;
    }
}

help anyone?