A Trapezoid is a Distorted 2 x 2 that can be formed from a normal 2 x 2 after any two adjacent dancers each move a distance of one matrix position directly away from each other.
From a 2 x 4, there are two Trapezoids. The Ends of one side work with the Centers of the other side within a Distorted Box.
© Vic Ceder. All Rights Reserved. Used with permission.