Quadrilateral ABCD would be a rhombus if all sides of the quadrilateral are also equal in length. Also add on the fact that none of the angles are right angles.
A)If the order of the speakers is important, we have 20x19x18x17, or 116,280 different options. b) If order is not important, then we have 20 choose 4, or 4845 different slates. ☺☺☺☺
