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.

Trapezoid Formation:

From here...   imagine you are here...   or here.

• The traffic pattern for some Trapezoid calls can be horrendous. Use Stars as necessary and try to get to your ending position without colliding with any other dancers.
• Calls must end on original Trapezoid footprints. Shape-changing calls are not allowed.

Trapezoid Couple Up:     before Trapezoid Couple Up   after

Once Removed Trapezoid Counter Rotate 1/4: (This is very difficult, even at C4)     before Once Removed Trapezoid Counter Rotate 1/4   after

See also Magic Line | Wave CONCEPT [C3B] which (from Parallel Lines) involves the same footprints, but dancers work within a Distorted Line instead of a Distorted Box.