Step 1: Find the total area. Since it is a square all the sides are 12 ft so multiply 12 by 12
12 x 12 = 144
^^^This is the total area including the area around the pool. We just need the are of the pool
Step 2: Outside of the pool there are four little 2 ft by 2 ft squares that aren't part of pool, and therefore won't need to be covered. The area of these 2 ft by 2 ft square is 4ft (2 times 2 is 4). Since there are 4 of these squares we multiply 4 by 4 to get 16. This means that 16 ft of the 144 ft we found previously are not part of the pool and we must subtract 16 from 144 to get the total pool area
144 - 16 = 128
This means that the area of the pool is 128 ft
Hope this helped and made sense! Let me know!