title: Unity 2D C# hitbox with boxcollider
body: <p>I have some game objects on screen and added a polygon collider on them to detect normal collision with them. I would like to add a box collider on their head to detect headshot. How can i do this please? How can i state collision with box collider instead of polygon collider in C# please? </p>
  
  <p>i tried this but only the polygon collider is getting detected</p>
  
  <pre><code>void OnCollisionEnter2D(Collision2D col) {
      if(col.gameObject.tag == "target")
      {
          score += 1000;
          gameObject.SetActive (false);
          gameObject.SetActive (true);
          Destroy (col.gameObject);
      }
      else if(col is BoxCollider2D)
      {
          score += 2000;
          gameObject.SetActive (false);
          gameObject.SetActive (true);
          Destroy (col.gameObject);
      }
  }
  </code></pre>