Answer:
8 ft × 10 ft = 80 ft
The bit at the end is a semi-circle and its diameter is 8ft, the formaula to find its circumference is (Diameter × π) = 8π but this is half a circle so
8π ÷ 2 = 4π
Now to find the area of the pool, you have to minus 4π by 80
80 - 4π = 67.4 (3 significant figures)