



3D Shapes
There are many types of threedimensional shapes. You've surely seen spheres and cubes before. In this lesson, you'll learn about polyhedra — threedimensional shapes whose faces are polygons — and you'll also learn about two special types of polyhedra: prisms and pyramids.
Polyhedra
A die is in the shape of a cube. A portable DVD player is in the shape of a rectangular prism. A soccer ball is in the shape of a truncated icosahedron. These shapes are all examples of polyhedra.
A threedimensional shape whose faces are polygons is known as a polyhedron. This term comes from the Greek words poly, which means "many," and hedron, which means "face." So, quite literally, a polyhedron is a threedimensional object with many faces.
The faces of a cube are squares. The faces of a rectangular prism are rectangles. And the faces of a truncated icosahedron are pentagons and hexagons — there are some of each.
The other parts of a polyhedron are its edges, the line segments along which two faces intersect, and its vertices, the points at which three or more faces meet.
Next: Explore PrismsExplore Prisms




