(Geometry: n-sided regular polygon) In an n-sided regular polygon all sides have the same length and all angles have the same degree (i.e., the polygon is both equilateral and equiangular).  Design a class named RegularPolygon that contains:

• A private int data field named n that defines the number of sides in the polygon with default values 3.
• A private double data field named side that stores the length of the side with default value 1.
• A private double data field named x that defines the x-coordinate of the polygon’s center with default value 0(zero).
• A private double data field named y that defines the y-coordinate of the polygon’s center with default value 0(zero).
• A no-arg constructor that creates a regular polygon with default values.
• A constructor that creates a regular polygon with the specified number of sides and length of side, centered at (0, 0).
• A constructor that creates a regular polygon with the specified number of sides, length of side, and x-and y-coordinates.
• The accessor and mutator methods for all data fields.
• The method getPerimeter() that returns the perimeter of the polygon.
• The method getArea() that returns the area of the polygon.  The formula for computing the area of a regular polygon is

• The toString() method that returns a string representation of a RegularPolygon object

Write a test program, TestRegularPolygon, that creates three RegularPolygon objects, created using the no-arg constructor, using RegularPolygon(6, 4), and using RegularPolygon(10, 4, 5.6, 7.8).  For each object, display its area and perimeter.

RegularPolygon.java

/**
 * Regular Polygon. 
 */
public class RegularPolygon {

    // Declare and initialize default values.
    private int n		= 3;
    private double side	= 1.0;
    private double x	= 0.0;
    private double y	= 0.0;

    	// Create constructor with default values.
    	public RegularPolygon(){

    	}

    	// Create constructor with new n and side values.
    	public RegularPolygon(int n, double side){  		
    		this.n		= n;
    		this.side	= side;
    		this.x		= 0;
    		this.y		= 0;
    	}

    	// Create constructor with new n, side, x, and y values.
    	public RegularPolygon(int n, double side, double x, double y){	
    		this.n		= n;
    		this.side	= side;
    		this.x		= x;
    		this.y		= y;	
    	}

    	// get n method
    	public int getN(){
    		return this.n;
    	}

    	// set n method.
    	public void setN(int n){
    		this.n	= n;
    	}

    	// get side method.
    	public double getSide(){
    		return this.side;
    	}

    	// set side method.
    	public void setSide(double side){
    		this.side = side;
    	}

    	// get x-coordinate method.
    	public double getX(){
    		return this.x;
    	}

    	// set x-coordinate method.
    	public void setX(double x){
    		this.x	= x;	
    	}

    	// get y-coordinate method.
    	public double getY(){
    		return this.y;
    	}

    	// set y-coordinate method.
    	public void setY(double y){
    		this.y	= y;
    	}

    	// Calculate Perimeter.
    	public double getPerimeter(){
    		return this.n * this.side;
    	}

    	// Calculate Area.
    	public double getArea(){
    		return (this.n * Math.pow(this.side,2)) / (4 * Math.tan(Math.PI/this.n));
    	}

    	// Pepresentation method of RegularPolygon object.
    	public String toString(){
    		String result;
    		if(this.n >= 3 && this.side > 0){
    			result = "The Regular Polygon n: " + this.n + ", side: "+ this.side + ", Area: " + this.getArea() + ", Perimeter: " + this.getPerimeter();
    		}else if(this.n >= 3 && this.side <= 0){
    			result = "The side length must be greater than zero.";
    		}else if(this.n < 3 && this.side > 0){
    			result = "The number of edges must be greater than three.";
    		}else{
    			result = "The side length must be greater than zero and the number of edges must be greater than three.";
    		}
    		return result;
    	}

} // End of RegularPolygon class.

TestRegularPolygon.java

/**
 * Regular Polygon. 
 */
public class TestRegularPolygon{
	/** main Method */
	public static void main(String [] args){

		// Create RegularPolygon object.
		RegularPolygon reg0	= new RegularPolygon();
		RegularPolygon reg1	= new RegularPolygon(6,4);
		RegularPolygon reg2	= new RegularPolygon(10,4,5.6,7.8);

			// Print RegularPolygon object values.
			System.out.println(reg0);
			System.out.println(reg1);
			System.out.println(reg2);
	} // End of main method

} // End of TestRectangle class.