Question

JAVA PROGRAMMING: Every circle has a center and a radius. Given the radius, we can determine the circle’s area and circumference. Given the center, we can determine its position in the x-y plane. The center of a circle is a point in the x-y plane. Design the class Circle that can store the radius and center of the circle. Because the center is a point in the x-y plane and you designed the class to capture the properties of a point in Programming Exercise 3, you must derive the class Circle from the class Point. You should be able to perform the usual operations on a circle, such as setting the radius, printing the radius, calculating and printing the area and circumference, and carrying out the usual operations on the center.

Answer 1

class Point {
        private int x;
        private int y;

        public Point(int x, int y) {
                this.x = x;
                this.y = y;
        }

        @Override
        public String toString() {
                return "Point (" + x + ", " + y + ")";
        }

        public int getX() {
                return x;
        }

        public int getY() {
                return y;
        }

        public void setX(int x) {
                this.x = x;
        }

        public void setY(int y) {
                this.y = y;
        }
}

class Circle extends Point {
        private int radius;

        public Circle(int x, int y, int radius) {
                super(x, y);
                this.radius = radius;
        }

        public int getRadius() {
                return radius;
        }

        public void setRadius(int radius) {
                this.radius = radius;
        }

        public void printArea() {
                double area = Math.PI * radius * radius;
                System.out.println("Area: " + area);
        }

        public void printCircumference() {
                double c = 2 * Math.PI * radius;
                System.out.println("Area: " + c);
        }
}