Question

Problem 2 9.9 Geometry: n-sided regular polygon pg. 362 (25 points) Follow instructions as provided on page 362, reprinted below 9.9 (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 value of 3 A private double data field named side that stores the length of the side with default value of 1 A private double data field named x that defines the x-coordinate of the polygon's center with default value of 0 A private double data field named y that defines the y-coordinate of the polygon's center with default value of 0 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 Create a get and set method for each of the properties. 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 Area-(n * side side)/ (Math.tan(Math.PI / n) * 4) Draw the UML diagram for the class and then implement the class. Write a test program 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 perimeter and area

Answer 1

UML class diagram

//program in java

import java.lang.*;
//--------------------------
class RegularPolygon{
   private int n;
   private double side;
   private double x;
   private double y;
   //default constructor
   public RegularPolygon(){
       n=3;
       side=1;
       x=y=0;
   }
   //parameterized constructor
   public RegularPolygon(int m,double len){
       n=m;
       side=len;
       x=y=0;
   }
   //parameterized constructor
   public RegularPolygon(int m,double len,double a,double b){
       n=m;
       side=len;
       x=a;
       y=b;
   }
   public void setNumberOfSide(int m){
       n=m;
   }
   public void setSideLength(double len){
       side=len;
   }
   public void setXcoordinate(double a){
       x=a;
   }
   public void setYcoordinate(double b){
       y=b;
   }
   public int getNumberOfSide(){
       return n;
   }
   public double getSideLength(){
       return side;
   }
   public double getXcoordinate(){
       return x;
   }
   public double getYcoordinate(){
       return y;
   }
   //finds perimeter
   public double getPerimeter(){
       return n*side;
   }
   //find area
   public double getArea(){
       double area=(n*side*side)/(Math.tan(Math.PI/n)*4);
       return area;
   }
}
//----------main class-------------
public class RegularPolygonMain{
   public static void main(String args[]){
       RegularPolygon p1=new RegularPolygon();
       RegularPolygon p2=new RegularPolygon(6,4);
       RegularPolygon p3=new RegularPolygon(10,4,5.6,7.8);
       System.out.println("perimeter= "+p1.getPerimeter());
       System.out.println("Area= "+p1.getArea());
       System.out.println("perimeter= "+p2.getPerimeter());
       System.out.println("Area= "+p2.getArea());
       System.out.println("perimeter= "+p3.getPerimeter());
       System.out.println("Area= "+p3.getArea());

   }
}
//------------------------

ouput: