# 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

## 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)