1) A rectangular pool is 60 feet long by 30 feet wide.  The shallow end is 4 feet deep and the deep end is 8 feet deep.  Find the surface area and the volume.

2) A circular spa has a 10 foot diameter and a constant depth of 4 feet deep.  Find the surface area and the volume.

3) A rectangular pool has a swimming area and a diving well.  The swimming area is 75 feet long by 25 feet wide and is 3 feet deep to 5 feet deep.  The diving well is 25 feet long by 25 feet wide and has a constant depth of 10 feet deep.  Find the total volume.  (Hint:  Split the pools, then find the volume of each and add totals.)

FORMULAS

Surface Area (Rectangle/Square):  Length  x  Width
Volume (Circle/Rectangle/Square): Surface Area x Average Depth x 7.5
Average Depth: (Shallow Depth + Deep Depth) ÷ 2
(Note: Constant Depth = Average Depth)

EXAMPLE

A rectangular pool is 50 feet long by 20 feet wide.  The shallow end is 3 feet deep and the deep end is 7 feet deep.  Find the surface area and the volume.

Surface Area = Length  x  Width
Surface Area = 50 feet  x  20 feet
Surface Area = 1,000 square feet

Volume = Surface Area  x  Average Depth  x  7.5
Volume = 1,000  x  Average Depth  x  7.5
Average Depth = (Shallow Depth + Deep Depth) ÷ 2
Average Depth = (3 + 7) ÷ 2
Average Depth = 10 ÷ 2
Average Depth = 5
Volume = 1,000  x  5  x  7.5
Volume = 37,500 Gallons