Exactly how many triangles can you count in this fun triangle puzzle?

As electric-white movie star smiles become increasingly popular, more and more people seek to correct their dental imperfections. Black triangles between your teeth, called open gingival embrasures, ...

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 ...

Design Squad is available to stream on pbs.org and the free PBS App, available on iPhone, Apple TV, Android TV, Android smartphones, Amazon Fire TV, Amazon Fire Tablet, Roku, Samsung Smart TV, and ...