Area of a circle

The area of a circle is the number of square units within the circle. To calculate the area of a circle the standard formula is: Area = Pi R Square

Area of circle = (A = πr²)

Logic

Here we have taken radius as input from the user, and to calculate the area of the circle we have to multiply the value of pi with a square of the radius.

Value of Pi = (3.14159)

Program

AreaOfCircle.CCopy
#include<stdio.h>

int main() {

    float radius, area;
    
    printf("Enter radius of the circle : ");
    scanf("%f", &radius);

    area = 3.14 * (radius * radius);

    printf("\nArea of circle : %f" , area);

    return 0;
}
Try It

Output

Enter radius of the circle : 25.125
Area of circle : 1982.174072

Know more about Pi? – What is Pi?