C Program to Find Area of Circle

In this example, We are going to find area of circle. So firstly we should know formula for calculating Area of any Circle;

Circle Area is the multiplication of square of radius and PI . Where PI is a constant which value is 3.14.

C Program to Find Area of Circle

#include<stdio.h>
#define PI 3.14
void main()
{
   float radius, area;
   printf("Enter value of Radius");
   scanf("%f",&radius);
   area = radius * radius * PI;
   printf("Area of the Circle = %.2f",area);
} 

Output

Enter value of Radius
9
Area of the circle = 254.34

Explanation

In this program, We calculated area of the Circle using c program. For this we have define a constant “PI” using preprocessor (#).