parallelogram rule

18 LETTERS · STARTS WITH P

parallelogram rule is a valid 18-letter word worth 22 points in Scrabble and 30 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

P3A1R1A1L1L1E1L1O1G2R1A1M3R1U1L1E1

3 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 2 + 1 + 1 + 3 + 0 + 1 + 1 + 1 + 1 =22 PTS

DOUBLE WORD → 44TRIPLE WORD → 66

MEANING

What does parallelogram rule mean?