```cpp #include <math.h> #define PI 3.141592654 double radius = 5; double circle_area = PI*(Pow(rad

#include <math.h>

#define PI 3.141592654
double radius = 5;
double circle_area = PI*(Pow(radius, 2));

// Area of cercle is on variable 'circle_area'

#include <math.h>

#define PI 3.141592654
double radius = 5;
double circle_area = PI*(Pow(radius, 2));

// Area of cercle is on variable 'circle_area'