Vector3Cross.cs

using UnityEngine;

public class VectorOperations : MonoBehaviour
{
    [SerializeField] private Vector3 _vectorA;
    [SerializeField] private Vector3 _vectorB;
    [SerializeField] private Vector3 _vectorC;

    private Vector3 _side1;
    private Vector3 _side2;

    private Vector3 GetNormal(Vector3 _vectorA, Vector3 _vectorB, Vector3 _vectorC)
    {
        _side1 = _vectorB - _vectorA;
        _side2 = _vectorC - _vectorA;
        return Vector3.Cross(_side1, _side2).normalized;
    }
}