C++ Programming Code Examples
C++ > Computer Graphics Code Examples
Calculate Area and Circumference of Circle
/* Calculate Area and Circumference of Circle
To calculate area and circumference of any circle in C++ Programming, you have to ask to the user to enter the radius of circle, place the radius in a variable say r and make two variable, one for area and other for circumference, and place 3.14*r*r in area and 2*3.14*r in circumference, then display the result on the screen as shown here in the following program.
Following program ask to the user to enter the radius of a circle, to calculate and display the area and perimeter of the circle: */
#include<iostream.h>
#include<conio.h>
void main()
{
clrscr();
float r, area, circum;
cout<<"Enter the radius of the circle :";
cin>>r;
area=3.14*r*r;
circum=2*3.14*r;
cout<<"Area of the circle = "<<area<<"\nCircumference of the circle = "<<circum<<"\n";
getch();
}
It is a predefined function in "conio.h" (console input output header file) used to clear the console screen. It is a predefined function, by using this function we can clear the data from console (Monitor). Using of clrscr() is always optional but it should be place after variable or function declaration only. It is often used at the beginning of the program (mostly after variable declaration but not necessarily) so that the console is clear for our output.
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