I think that there is an incorrect test case for this community puzzle (it's currently the puzzle of the week).
The last test case is:
H -4 3 A 2 5 R 4 2 D 10 4
J -2 0 A 0 1 C 2 0 K 0 -1
A 1 -2 B 5 0 C 3 4 D -1 2
HARD is a quadrilateral.
JACK is a rhombus.
ABCD is a square.
I drew the first first quadrilateral (HARD) and I think it should be expecting a parallelogram, not just quadrilateral, because it has two pairs of equal sides that are parallel with each to other.
I submitted my solution and got 100% score, even though it did not passed on this test case. If you already solved, I think you can have a look at my solution here.
I also checked some public solutions, could not find one that don't successfully pass on the last test case as mine.