7' square => 49 sft
7' dia circle => 38 sft
14 x 28 => 392 sft - (49-38) => 381 sft (w/ radius corners)

volume of 3' deep 'slice' of pool: 381*3*7.46 gal/cft = 8,500 gallons

assuming deep section begins at 1/3 of 28 - 9.33'

assuming *additional* average depth of deep section is 1.25'

deep 'slice' is 14 x 18.67 x 1.25 x 7.46 = 2,400 gal

Total volume = 2,400 + 8,500 or 10.9k gallons. PF=11