how can i find angle from object of world axis ??

how can i find angle from object of world axis ?? i try to make angle but thats not working

Vector3 worldDir = Vector3.right;
             newAngle = Vector3.Angle(worldDir, transform.forward);

how can i get angle object of world axis ??, maybe there is another way ??

what seems to be the problem? do you need Vector3.SignedAngle?