Take learning geometry to a new dimension and reinforce the basics with our GeoModel™ relational solids. Made of durable plastic, each hollow GeoModel™ solid features a removable base and stopper for use with any dry or liquid fill. Shapes are relational in size, each measuring 5 cm (2 inches) in height to better demonstrate the properties of the solids and the parallels involving shape, volume, and surface area. Activity Book included. Grades 3+.