Enable and disable Children gameobject c #

Well, I made a script where it activates and deactivates in the gameobject , I wanted to know how to activate and deactivate the children also inside this script

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class OBJETOS : MonoBehaviour
{
    public GameObject[] arrayObjetos;

    public void botoes(int num)
{
    for(int i = 0; i < arrayObjetos.Length; i++)
{
    if( arrayObjetos[num] == arrayObjetos[i])
{
    arrayObjetos[i].SetActive(true);
    }else{
    arrayObjetos[i].SetActive(false);
}
}
}
}
//sei que pode ser assim GameObject meuobjeto = GameObject.Find("meuobjeto");
// e assim tbm GameObject ChildGameObjeto1 = ParentGameObject.transform.GetChild (0).gameObject;