A gallon is a measure of volume and that means that it normally requires three measurements: for example, length, breadth and height. The question provides only two.
You need more information. But, let's assume the pool is 8 feet deep at the deep end and 3 feet at the shallow end. If the pool is rectangular, the total volume will be 28,798 gallons of water.
About 10 gallons
781.987 gallons.
500 gallons.
92 gallons
You can fit 8 gallons in 8 gallons.
There are 3 gallons
840 half-gallons.
There are 144 gallons in 576 gallons.
There are precisely 107026920 gallons in 107026920 gallons!
7.5 gallons
7.91888967 imperial gallons = 9.51019 US gallons.