The swimming pool shown below is a right prism with concave hexagonal bases. The owners of the pool want to paint the sides and bottom of the pool. If one gallon of paint covers 400 square feet, how many gallons of paint will be needed to paint the inside of the pool?

3 bottom sections:

10 x 20 = 200

5x 20 = 100

10 x 20 = 200

Bottom area = 200 + 200 + 100 = 500 square feet.

Short side: 3 x 20 = 60

Deep end wall : 6 x 20 = 120

Side wall : (24 x6) - (10x3) - (1/2 x 4x3) = 144-30-6 = 108

2 side walls: 108 x 2 = 216

Total area : 500 + 216 + 60 + 120 = 896 square feet

Divide total area by area of 1 gallon:

896/400 = 2.24 gallons

It will take 2.24 gallons of paint