Question

Write a Circle class that has the following member variables: • radius: a double • pi: a double initialized with the value 3.14159 The class should have the following member functions: • Default Constructor. A default constructor that sets radius to 0.0. • Constructor. Accepts the radius of the circle as an argument. • setRadius. A mutator function for the radius variable. • getRadius. An accessor function for the radius variable. • getArea. Returns the area of the circle, which is calculated as area = pi * radius * radius • getDiameter. Returns the diameter of the circle, which is calculated as diameter = radius * 2 • getCircumference. Returns the circumference of the circle, which is calculated as circumference = 2 * pi * radius Write a program that demonstrates the Circle class by asking the user for the circle’s radius, creating a Circle object, and then reporting the circle’s area, diameter, and circumference.

SAMPLE RUN : ./circle_Non-Interactive Calling·defeault·constructor:·The·circle's·radius·in·the·default·Circle·Object·is:·0↵
↵
Calling·setRadius(20)·to·change·radius·of·default:↵
The·circle's·radius·in·the·default·Circle·Object·is·Now:·20↵
↵
Creating·Circle·circle2(10):·↵
The·circle2's·radius·in·the·circle2·Object·is:·10↵
↵
The·circle2's·area·is·therefore:·314.159↵
The·circle2's·diameter·is·therefore:·20↵
The·circle2's·circumference·is·therefore:·62.8318↵

Answer 1

NOTE

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As the programming language is not specified, c++ is used

//##################### PGM START #################################

#include<iostream>
using namespace std;

class Circle{
   private:
       double radius;
       double pi=3.14159;
  
   public:
       //default constructor
       Circle(){
           radius=0.0;
           cout<<"The·circle's·radius·in·the·default·Circle·Object·is 0\n";
       }
       //parameterized constructor
       Circle(double r){
           radius=r;
           cout<<"The circle radius is set to "<<r<<"\n";
       }
       //accessor for radius
       double getRadius(){
           return radius;
       }
       void setRadius(double r){
           radius=r;
       }
       double getArea(){
           return pi*radius*radius;
       }
       double getDiameter(){
           return 2*radius;
       }
       double getCircumference(){
           return 2*pi*radius;
       }
};
///main method
int main(){
   double radi;
  
   //requesting circle radius from user
   cout<<"Enter the circle radius: ";
   cin   >>radi;
  
   //creating circle object with the entered radius
   Circle c1(radi);
  
  
   //calculating area, diameter and perimeter of circle
   cout<<"The circle's areas is: "<<c1.getArea()<<"\n";
   cout<<"The circle's diameter is: "<<c1.getDiameter()<<"\n";
   cout<<"The circle's circumference is: "<<c1.getCircumference()<<"\n";
  
   return 0;
}

//############################ PGM END #############################

OUTPUT
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