Brian likes to grow cactus plants in his kitchen window. He has read that around 90 percent of a cactus's volume is used for water storage. He wondered which of two types of cacti in the window could hold the most water, so he decided to estimate their volumes to make a comparison. Brian's measurements are shown in the diagram below. For the column cactus the density = 4.5cm and the height =16cm for the barrel cactus the density = 8cm and the height = 8cm. Assume that the shapes fill the given dimensions. Don't take into account gaps or spines on the surface when determining the volume. Calculate the approximate volume of each cactus using 3.14 for π. ​