Broken Parallelogram - basic coordinates activity

Rob Street
This should be a parallelogram. One coordinate is wrong. Work out which coordinate you want to move and to where. Then only edit that coordinate in the box on the left. Did it make a parallelogram?
Starting with the initial coordinates (-2, 2), (4, 4), (8, 1), (0, -4), and moving only one point, how many different parallelograms can be made? What about using the same starting coordinates, and moving one point to make a trapezium?