A prism has a constant cross-section throughout its length. When the cross-section is a triangle, the prism is called a triangular prism. When the cross-section is a hexagon, the prism is called a ...

A 3D shape with all straight edges and flat faces is a polyhedron. Other 3D shapes with least one curved surface are not polyhedra. A 3D shape with regular polygonal faces, meeting at equal angles, is ...

This media is in the public domain (free of copyright restrictions). You can copy, modify, and distribute this work without contacting the Smithsonian. For more information, visit the Smithsonian's ...

IIIF provides researchers rich metadata and media viewing options for comparison of works across cultural heritage collections. Visit the IIIF page to learn more. This is the ninth in a series of ...

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. 00:00:00:00 ED LEMBKE-HOGAN: Did you know that there are 138 known pyramids in Egypt, all of them ...