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 ...

How few corners can a shape have and still tile the plane?” mathematician Gábor Domokos asked me over pizza. His deceptively simple question was about the geometry of tilings, also called ...

Titch and Ted learn about geometry on their day out at the beach. Titch and Ted have had a lovely day at the beach, solving problems with 2D and 3D shapes and using the vocabulary of directions, ...

More than 50 activities connected to mathematical concepts—geometry, fractals, and tangrams, among others—are explored through 37 “labs” that feature step-by-step instructions and photographs. The ...