How could you calculate how much material is required for irregular shape of a body and how much paint required to paint?

To calculate the material required for an irregularly shaped body, you can use the water displacement method by submerging the object in water and measuring the volume of water displaced, which corresponds to the volume of the body. For painting, first determine the surface area by breaking the shape into smaller, regular shapes, calculating their areas, and summing them up. Then, check the paint coverage specified on the paint can (usually in square feet or meters per liter/gallon) and divide the total surface area by this coverage to find the amount of paint needed.