C Program for Program to find the area of a circle?

The area is a quantity that represents the extent of the figure in two dimensions. The area of a circle is the area covered by the circle in a two dimensional plane.

To find the area of a circle, the radius[r] or diameter[d](2* radius) is required.

The formula used to calculate the area is (π*r²) or {(π*d²)/4}.

Example Code

To find the area of a circle using radius.

 Live Demo

#include <stdio.h> int main(void) {    float pie = 3.14;    int radius = 6;    printf("The radius of the circle is %d 
" , radius);    float area = (float)(pie* radius * radius);    printf("The area of the given circle is %f", area);    return 0; }

Output

The radius of the circle is 6 The area of the given circle is 113.040001

Example Code 

To find the area of a circle using radius using math.h library. It uses the pow function of the math class to find the square of the given number.

 Live Demo

#include <stdio.h> int main(void) {    float pie = 3.14;    int radius = 6;    printf("The radius of the circle is %d 
" , radius);    float area = (float)(pie* (pow(radius,2)));    printf("The area of the given circle is %f", area);    return 0; }

Output

The radius of the circle is 6 The area of the given circle is 113.040001

Example Code 

To find the area of a circle using Diameter.

 Live Demo

#include <stdio.h> int main(void) {    float pie = 3.14;    int Diameter = 12;    printf("The Diameter of the circle is %d 
" , Diameter);    float area = (float)((pie* Diameter * Diameter)/4);    printf("The area of the given circle is %f", area);    return 0; }

Output

The Diameter of the circle is 12 The area of the given circle is 113.040001