Convert two contact points in world space to size width in rect

I have two contacts points inside a collision, and I have tried to transform these contacts in width of a new rect, for fake cut sprite purpose, I read all documentations about Rect, and Collision, and nothing helped me, can anyone give me a fresh breeze about that. this is the code:

 void OnCollisionEnter2D(Collision2D target)
     {
         
         // Make an empty list to hold contact points
         ContactPoint2D[] contacts = new ContactPoint2D[target.contactCount];
 
         // Get the contact points for this collision
         int numContacts = target.GetContacts(contacts);
 
         var sprite = GetComponent<SpriteRenderer>().sprite;
         var a = contacts[0].point;
         var b = contacts[contacts.Length - 1].point;
         Cut(a, b);
     }
 
 void Cut(Vector2 cutPositionA, Vector2 cutPositionB)
     {
         var sprite = GetComponent<SpriteRenderer>();
         Texture2D _texture = sprite.sprite.texture;
         Sprite newSprite = Sprite.Create(_texture, new Rect(cutPositionA.x, 0f, cutPositionB.x, 512f), new Vector2(0.5f, 0.5f), 512f);
 
         GameObject sprGameObj = new GameObject();
         sprGameObj.transform.localScale = sprGameObj.transform.localScale + new Vector3(1f, 1f, 0f);
         sprGameObj.AddComponent<SpriteRenderer>();
         SpriteRenderer sprRenderer = sprGameObj.GetComponent<SpriteRenderer>();
         sprRenderer.sprite = newSprite;
         sprGameObj.transform.position = new Vector3(cutPositionA.x, cutPositionA.y);
         sprRenderer.sortingOrder = 1;
         sprGameObj.AddComponent<BoxCollider2D>();
         var bc = sprGameObj.GetComponent<BoxCollider2D>();
         bc.offset = new Vector2(0f, 0.06f);
         bc.size = new Vector2(1f, 0.7f);
         var rb = sprGameObj.AddComponent<Rigidbody2D>();
         rb.drag = 2f;
         rb.angularDrag = 3f;
         rb.mass = 1f;
     }