C Program to Calculate Area Of a Circle

Area of Circle in C

Here, in this page we will discuss the program to find area of circle in C programming language.

The area of a circle can be found by using the formula:
Area of circle= 𝝅*R* R , or
Area of circle = (𝝅*D* D)/4

Area of circle in C

Working:-

  • User gives an input
  • The input is stored in a float type variable say radius.
  • Another float type variable is taken say area and variable pi initialized with 3.14.
  • Now using the formula we find the area of the circle of radius radius and store it in area.

                          area= pi* radius* radius;

  • Print the value of area.

Code in C

#include<stdio.h>

int main(){
    float r =3, pi=3.14, area;
    
    area=pi*r*r;
    printf("Area of circle is %.2f", area);
}

Output

Area of circle is 28.26

Algorithm using diameter:-

  • User gives an input
  • The input is stored in a float type variable say d.
  • Another float type variable is taken say area and variable pi initialized with 3.14.
  • Now using the formula we find the area of the circle of diameter d and store it in area.

                          area= (pi* d* d)/4;

  • Print the value of area.

Code in C

#include<stdio.h>

int main(){
    float d = 6, pi=3.14, area;
    
    area=(pi*d*d)/4;
    printf("Area of circle is %.2f", area);
}

Output

Area of circle is 28.26

One comment on “C Program to Calculate Area Of a Circle”


  • Soumya

    For python
    r=int(input(“Enter a radius of a circle : “))
    area=3.141592*r*r
    print(“Area of the circle is “,area)