Named for Plato, who theorized that the classical elements were made of these regular polyhedrons, three of the Platonic solids are composed of equilateral triangles: the tetrahedron, octahedron, and ...

Two-dimensional (2D) shapes are completely flat. They cannot be picked up. A polygon is a 2D shape with straight sides that meet at vertices. Polygons have names that show the number of sides they ...

Two-dimensional (2D) shapes are completely flat. They cannot be picked up. 2D shapes can be found printed in a book or you can draw them on a piece of paper. 2D shapes have sides and corners (also ...

Help children to use, discuss and think about shapes in mathematical terms with suggestions from Sheila Ebbutt and Carole Skinner. Shapes of things we can see or touch are mostly too complex to ...