There are approximately 1,870 gallons of water in a 27-foot-round, 52-in-high swimming pool. To find the answer, use the formula for finding the volume of a cylinder, V = pi r^2 h, then convert cubic feet to gallons.
To find the radius, divide the circumference by 2 pi. In this case, the radius of the pool is approximately 4.3 feet. Take the square of 4.3 feet and multiply by pi. This yields an area of 58.1 square feet. Converting 52 inches to feet gives a pool height of approximately 4.3 feet. Multiply 58.1 x 4.3 to get a volume of approximately 250 cubic feet. Since there are 7.48 gallons per cubic foot, multiply 250 x 7.48 to get 1,870 gallons.