Get the perfect ratio and proportion products to make your classroom interactive! Get geometric solids, big or small, to show students volume by filling the shapes with liquid or solids! Comes with a guide and is easy to clean. With our Polydron sets students get to learn about the 5 platonic solids or build any 3-D shape they want. Use our graph paper, protractors, and compasses to compare shapes' size and proportion to each other.