Question

java

Define the Circle2D class that contains: • Two double data fields named x and y that specify the center of the circle with get methods. A data field radius with a get method. • A data field radius with a get method. • A no-arg constructor that creates a default circle with (0, 0) for (x, y) and 1 for radius. • A constructor that creates a circle with the specified x, y, and radius. • A method getArea() that returns the area of the circle. • A method getPerimeter() that returns the perimeter of the circle. • A method contains(double x, double y) that returns true if the specified point (x, y) is inside this circle (a) • A method contains(Circle2D circle) that returns true if the specified circle is inside this circle(b) • A method overlaps(Circle2D circle) that returns true if the specified circle overlaps with this circle(c)

Answer 1

import java.lang.Math;

public class Circle2D {
        
        // Data fields for center of the circle.
        private double x;
        private double y;
        
        // Data field for the radius of the circle.
        private double radius;
        
        // A no-argument constructor that creates a circle with (0,0) for (x,y) and 1 for radius.
        Circle2D() {
                x = 0;
                y = 0;
                radius = 1;
                }
        
        // A constructor that creates a circle with the specified x, y, and radius.
        Circle2D(double x, double y, double radius) {
                        this.x = x;
                        this.y = y;
                        this.radius = radius;
                }
        
        // A get method for x.
        public double getX() {
                return x;
        }
        
        // A get method for y.
        public double getY() {
                return y;
        }

        // A get method for radius.
        public double getRadius() {
                return radius;
        }
        
        //  A method that returns the area of the circle. 
        public double getArea() {
                double Area = Math.PI *radius*radius; // Area of circle pi*r^2.
                return Area;
        }
        
         // A method that returns the perimeter of the circle.
        public double getPerimeter() {
                double Perimeter = 2*Math.PI *radius; // Perimeter of circle 2*pi*r.
                return Perimeter;
        }
        
        /* A method that returns true if the specified point (x, y) is inside this circle.
         * Logic : If the distance of given point(x,y) from center is less then radius of
         * the circle, then the point will lie inside the circle.
         */
        public boolean Contains(double x, double y) {
                double SqrDist = Math.pow((this.x - x),2) + Math.pow((this.y - y),2);
                double Dist = Math.sqrt(SqrDist);
                if (Dist < radius ) {
                        return true;
                } else {
                        return false;
                }
        }
        
        /* A method that returns true if the specified circle is inside this circle.
         * Logic : If the sum of the distance between the centers of the circles and
         *  smaller radius is lesser than the bigger radius, then smaller is inside the bigger circle.
         */ 
        public boolean Contains(Circle2D circle) {
                double SqrCentersDist = Math.pow((this.x - circle.getX()),2) + Math.pow((this.y - circle.getY()),2);
                double CentersDist = Math.sqrt(SqrCentersDist);
                double SmallRadius = circle.getRadius();
                
                if ( (CentersDist + SmallRadius) < radius) {
                        return true;
                } else {
                        return false;
                }
                
        }
        
        /* A method that returns true if the specified circle overlaps with this circle.
         * Logic : If sum of the distance between the centers of the circles is less than
         * sum of smaller radius and big radius and greater than difference of big radius and    small radius.
         * then these two circle will overlap.
         */
    public boolean Overlaps(Circle2D circle) {
        double SqrCentersDist = Math.pow((this.x - circle.getX()),2) + Math.pow((this.y - circle.getY()),2);
        double CentersDist = Math.sqrt(SqrCentersDist);
        double SmallRadius = circle.getRadius();
        
        if ((CentersDist<(radius + SmallRadius)) && (CentersDist>(radius - SmallRadius))) {
            return true;
        } else {
            return false;
        }
        
    }
        
}

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If you want to test this class:

public class Test {

        public static void main(String[] args) {
                // TODO Auto-generated method stub
                Circle2D circle1 = new Circle2D(5,5,10);
                Circle2D circle2 = new Circle2D(5,5,2);
                
                System.out.println("Center = (" + circle1.getX() + ", " + circle1.getY() + ")" );
                System.out.println("Radius = " + circle1.getRadius());
                System.out.println("area = " + circle1.getArea());
                System.out.println("parameter = " + circle1.getPerimeter());
                System.out.println("Is circle1 Contains (1.5, 0.5) = " + circle1.Contains(1.5, 0.5));
                System.out.println("Is circle1 Contains circle2 = " + circle1.Contains(circle2));
                
        }

}