Help me in solving VADD5 problem

My issue

My code

#include <stdio.h>

int main() {
  double pi = 3.14 ;
  double radius = 8.9 ;      //radius has to be declared as a 'double'
  double area = pi  * radius * radius;
  printf("the Area of the given Circle is %lf ", area); 
  return 0;

Learning course: Learn C
Problem Link: CodeChef: Practical coding for everyone