(cheerful music) (electronic gadgets whirring and ringing) - [Children] Math Mights! Welcome, 2nd grade Math Mights. My name is Mrs. McCartney. I'm so excited that you've joined us today for our show.

3D shapes can be made from 2D shapes called nets. Watch the video to learn how 3D shapes, such as a cube, can be created from nets, an arrangement of 2D shapes. Let's talk about nets. More ...

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 ...