Compilare: user.cpp: In function ‘int main()’: user.cpp:20:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("paralelogram2.in", "r", stdin); ^ user.cpp:21:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("paralelogram2.out", "w", stdout); ^ user.cpp:23:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &T); ^ user.cpp:27:82: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lf%lf%lf%lf%lf%lf%lf%lf", &xa, &ya, &xb, &yb, &xc, &yc, &xd, &yd); ^