The question reads: "A swimming pool is 15.0 m wide, 24.0 m long, 1.00 m deep at one end, and 2.60 m deep at the other end. How many cubic meters of water can it hold? (The slope on the bottom is constant."
I tried solving it by turning one of the polygonal sides into a right triangle with a 1.60 m leg (2.60 - 1.00) and a hypotenuse of 24 and a rectangle with area 24 (24.0 m x 1.00 m), added up the total area, and multiplied it by the width of the pool. Does that make sense?
The simplest way to handle this is to look at it "from the side". You get a trapezoid with "height" (length of the pool) 24.0 m, one "base" (depth at one end) 1.00 m. and the other "base" (depth at the other end) 2.60 m which has area (1/2)(1.00+ 2.60)(24.0). The volume is that area times the width, 15.0 m.