Circumference Of Circle C Example Program


When a circle's diameter is 1, its circumference is π. When a circle's radius is 1—called a unit circle—its circumference is 2π.


The circumference of a circle is written

π = C / d

Or, equivalently, as the ratio of the circumference to twice the radius. The above formula can be rearranged to solve for the circumference:

C = π * d = 2π * r


r = Radius
π = ~3.14

Circumference Of Circle Example Program

/*##Circumference Of Circle*/
/*##Calculation Programs, Datatype Programs, Basic Programs*/


float PI = 3.14;

int main(){
   float radius, ci;

   printf("\nEnter the radius of Circle : ");
   scanf("%f", &radius);

   ci = 2 * PI * radius;
   printf("\nCircumference of Circle : %f", ci);

   return (0);

Sample Output

Enter the radius of Circle : 2

Circumference of Circle : 12.560000