[salamander5]

There are 7.5 gallons in one cubic foot of water. How many gallons of water would it take to fill up a pool 30 feet long, 18 feet wide, 4 feet deep at the beginning and then sloping down to 8 feet deep towards the end (maintain a constant slope). Does anyone know how to solve this?? (And then tell me how you did it!) Thanks!

[Perito]

There are 7.5 gallons in one cubic foot of water. How many gallons of water would it take to fill up a pool 30 feet long, 18 feet wide, 4 feet deep at the beginning and then sloping down to 8 feet deep towards the end (maintain a constant slope).

The figure shows a cross section of the pool looking at the side (it's not to scale). You break the problem down into two problems. Find the area of the rectangle at the top (4 ft x 30 ft). Multiply that by the width and you have its volume. Find the area of the triangle at the bottom (base = 30 ft, height = 4 ft). Multiply that by the width of the pool and you have its volume.

You'll now have the entire pool's volume in cubic feet. Convert that to gallons using the conversion factor you were given and viola!

[salamander5]

Thanks for your help!