C PROGRAM TO CALCULATE AREA OF A CIRCLE

C
program for area of circle



#include

#define PI 3.141

int main(){

  float r, a;

  printf("Radius: ");

  scanf("%f", &r);

  a = PI * r * r;

  printf("%f\n", a);

  return 0;

}



Mathematical
formula for area of circle: 





















 



Here
Pie is constant which is equal to



Pie = 22/7 or
3.14159265358979323846264338327950288419716939937510...