(this exercise is a variation of the previous one) write a rectanglearea, squarearea, and circlearea methods that calculate and return the area of a rectangle, a square, and a circle, respectively. these methods will have the following signature: public double rectanglearea(double h, double w) public double squarearea(double s) public double circlearea(double r) test your methods by invoking them from the class constructor and printing in the constructor the values returned.