The image explains a simple method for calculating the water capacity of a cylindrical tank in liters. The formula used is Capacity (L) = (π × D² × H ÷ 4) × 1,000, where D represents the internal diameter of the tank in meters, H represents the actual water height in meters, and π is approximately 3.1416. The illustration also shows where the diameter and water height are measured, making the calculation easier to understand and apply in practical situations.

Using the example provided, the tank has an internal diameter of 2.0 meters and a water height of 2.5 meters. Substituting these measurements into the formula gives 7.854 cubic meters, which is converted to liters by multiplying by 1,000. The resulting water volume is approximately 7,854 liters. This calculation is useful for determining the amount of water stored in cylindrical tanks used onboard ships, in industrial facilities, and in other water-storage systems.