This topic focuses on deriving volume formulas for several three-dimensional shapes such as rectangular pyramids, cones, and spheres. The problems involve recognizing and applying the correct formula based on the dimensions provided for each shape. The math skills practiced include understanding geometric formulas for volume and applying these formulas to solve specific geometrical problems related to complex 3D shapes. This is part of a larger unit aimed at introducing the volume and surface area of complex 3D shapes in a geometrical context.