Rotate object A based on camera y rotation if angle is grather or less then

Hello, i want to rotate the belt object only if the camera object goes out of range between X and Y angle.

Right now the belt is fixed to the rotation of the cameraRotate.y

I have done some reasearch and found Vector3.sqrMagnitude, i know that this will help me find the position between 2 game objects can it be also used to find the anle ? or should i use the eulerAngle, if so how should the syntax be to put it in an if statment to make it update only after the camera reaches an angle which is grather on less then the last time it was updated ?

 public GameObject Camera;
 public GameObject Belt;

 public float DistanceToGround;
 public float DistanceToForward;

 public Vector3 cameraPosition;
 public Vector3 cameraRotate;

 private void FixedUpdate()
 {
     cameraPosition = Camera.transform.position;
     cameraRotate = Camera.transform.eulerAngles;


     Belt.transform.position = new Vector3(cameraPosition.x, cameraPosition.y - DistanceToGround, cameraPosition.z - DistanceToForward);
     Belt.transform.eulerAngles = new Vector3(Belt.transform.eulerAngles.x, cameraRotate.y +90, Belt.transform.eulerAngles.z);

 }