Learning Resources Relational GeoSolids. Teach shape, size and volume relationships with this set of plastic, translucent geometric shapes. These 3D maths resources are hollow and feature removable panels and stoppers that enable the user to fill them with rice or sand. Set includes 14 sizerelated shapes made up of spheres, cones, cubes, rectangles, cylinders, pyramids and polyhedras. Includes Teaching Guide. Shapes measure 5cm. Suitable for ages 8+