working out angle between two vectors unity code example

Example 1: get angle between two vectors unity

Vector3 targetDir = target.position - transform.position;
float angle = Vector3.Angle(targetDir, transform.forward);

Example 2: check the angle between two game objects unity

Vector3 dir = GameObject1.position - GameObject2.position;
 float angle = Mathf.Atan2(dir.y, dir.x) * Mathf.Rad2Deg;