The area of a circle is the space that the circle's closed shape takes, It can be calculated by using a formula.
Area = π r2 or area = 3.14*r*r
where
The perimeter or the circumference is the circle's boundary length.
The perimeter = 2 π r or can be written as pi D
where,
In the C++ program, Start with the user entering the value of the radius of the circle. Read the value to a variable r. Then calculate the area using the formula given above Area = 3.14 * r * r, Now display the value of Area.
Calculate the value of the perimeter using the formula Perimeter = 2 * 3.14 * r Finally display the value of the perimeter for the user.
Step 1: Call the header file iostream
.
Step 2: Use the namespace std
.
Step 3: Open the main function; int main().
Step 4: Declare float type variables r, area circum;
Step 5: Ask the user to enter the value of the radius of the circle.
Step 6: Get the value of the radius to the variable r.
Step 7: Calculate the area using the formula 3.14 * r * r;
Step 8: Get the value to the variable area;
Step 9: Display the result;
Step 10: Calculate the circumference using the formula 2 * 3.14 * r;
Step 11: Get the value to the variable circum;
Step 12: Display the result;
Step 13: Exit
#include<iostream>
using namespace std;
int main()
{
float r, area, circum;
cout<<"Enter the Radius of Circle: ";
cin>>r;
area = 3.14*r*r;
cout<<"\nArea of Circle = "<<area;
cout<<endl;
circum = 2*3.14*r;
cout<<"\nCircumference of Circle = "<<circum;
cout<<endl;
return 0;
}
Enter the Radius of Circle: 6 Area of Circle = 113.04 Circumference of Circle = 37.68