Check if position is inside Area using vertices

I have a few vertices, how can i determine if a player is inside the vertices area? The problem is vertices just exist in code, so i can’t use collider, and the vertices are Vector3 can’t use Rect.contains.
I appreciate your attention.

	public Vector3 verticeA;
	public Vector3 verticeB;
	public Vector3 verticeC;
	public Vector3 verticeD;


Solution using the center of vertices:

Bounds sectorBound = new Bounds (sector.centerLoc, new Vector3(50, 50, 10));