how do i check if my value match with other like a pair matching game

So i have a game with 9 boxes, there are 3 different number, each number spread 3 diferrent boxes at random position, every time i roll the wheel, 1 random number will be generate, which will open its corresponding. e.g if i roll number 3, box 3 will open... so far i've done that, but now i am stuck at how to detect that if they matching with the box i open before (mean if i open 2 box with same multiplier inside)

//here is my box class

public class Safe 
{
    public int multiplier;
    public GameObject reward;
    
}

 //and here is my gamemanager class
public class GameManager : MonoBehaviour
{
    public Text[] mText;
    public GameObject[] openBox;
    private int a, b, c;
    public Safe[] safe;
    // Start is called before the first frame update
    void Start()
    {
        GenerateRandom()
    }

    // Update is called once per frame
    void Update()
    {
        // this is where i check, e.g if i roll number 5, box 5 will open..
        switch (WheelController.finalAngle)
        {
            case 0:
                openBox[0].SetActive(true);
                mText[1].gameObject.SetActive(true);
                safe[1].reward.gameObject.SetActive(true);
                break;
            case 40:
                openBox[1].SetActive(true);
                mText[2].gameObject.SetActive(true);
                safe[2].reward.gameObject.SetActive(true);
                break;
            case 80:
                openBox[2].SetActive(true);
                mText[3].gameObject.SetActive(true);
                safe[3].reward.gameObject.SetActive(true);
                break;
            case 120:
                openBox[3].SetActive(true);
                mText[4].gameObject.SetActive(true);
                safe[4].reward.gameObject.SetActive(true);
                break;
            case 160:
                openBox[4].SetActive(true);
                mText[5].gameObject.SetActive(true);
                safe[5].reward.gameObject.SetActive(true);
                break;
            case 200:
                openBox[5].SetActive(true);
                mText[6].gameObject.SetActive(true);
                safe[6].reward.gameObject.SetActive(true);
                break;
            case 240:
                openBox[6].SetActive(true);
                mText[7].gameObject.SetActive(true);
                safe[7].reward.gameObject.SetActive(true);
                break;
            case 280:
                openBox[7].SetActive(true);
                mText[8].gameObject.SetActive(true);
                safe[8].reward.gameObject.SetActive(true);
                break;
            case 320:
                openBox[8].SetActive(true);
                mText[0].gameObject.SetActive(true);
                safe[0].reward.gameObject.SetActive(true);
                break;

        }
        Matching();

    }
    void GenerateRandom() //this is where i generate random Array 
    {
       a = Random.Range(15, 21);
        b = Random.Range(15, 21);
        c = Random.Range(15, 21);
        while ((a == b || b == c || a == c))
        {
            a = Random.Range(15, 21);
            b = Random.Range(15, 21);
            c = Random.Range(15, 21);
        } 
        for (int i = 0; i < mText.Length; i++)
        {
            if (i % 3==0)
            {
                mText[i].text = "x"+ a.ToString();
                safe[i].multiplier = a;
            }
            if (i % 3 == 1)
            {
                mText[i].text = "x" + b.ToString();
                safe[i].multiplier = b;
            }
            if (i % 3 == 2)
            {
                mText[i].text = "x" + c.ToString();
                safe[i].multiplier = c;
            }
        }
    }
    void Matching()
    {
        // I WANT TO CHECK IF THEY MATCHING AND WIN THE GAME. 
    }
}