public abstract class Shape {
    //protected int x, y;

    public String color;
    public abstract double computeArea( );
}

------------------



public class Rectangle extends Shape {

    double width, height;

    public Rectangle(double width, double height, String color) {
        this.width = width;
        this.height = height;
        super.color = color; <-------------------------------------

    }

    public double computeArea( ) {
        return width * height;
    }
}

------------


public class Circle extends Shape {
    double radius;


    public Circle(double radius) {
        this.radius = radius;
    }

    public double computeArea( ) {
        return Math.PI * radius * radius;
    }
}