To enter Radius of Circle and to calculate its Area.

 Program:

#include<stdio.h>

#include<conio.h>

#define pi 3.14

void main()

{

    float r, area;

    clrscr();

    printf("Enter Radius of Circle : ");

    scanf("%f", &r);

    area=pi*r*r;

    printf("Area of Circle is : %.2f square units", area);

    getch();

}

Output:

Enter Radius of Circle : 20

Area of Circle is : 1256.64 square units

Next Topic        :  Simple Interest Calculator

Previous Topic :  To enter Base and Height of a Triangle and to calculate it's Area