Consider a cylindrical storage tank with a conical top. The tank represents a composite body, which can be divided into a finite number of parts with simpler shapes. Pappus and Guldinus's theorems can be applied to find the surface area and volume of such composite shapes. To find the surface area, the generating curves for each shape are identified and revolved around a non-intersecting axis. Then, the centroid is located for each curve. The length of the generating curve and the distance traveled by the curve's centroid are then used to obtain the total surface area of the tank. Similarly, to estimate the volume, the generating area of each shape is identified and revolved around the same axis. The volume of a body of revolution is equal to the product of the generating area and the distance traveled by the centroid of the shape. By finding the area of each part and identifying their respective centroids, the values are substituted in the theorem to obtain the tank's volume.