720
Yes, 80x9=720
There are many but some are 90x8 80x9 2x360 20x36
720 sq ftWikipedia says "In West Bengal, the Bigha was standardized under British colonial rule at 1600 sq.yd ... "A kattha is 1/20 of a bigha; A square yard is 9 square feet.1600/20 = 80; 80x9 = 720.