3-D shapes (age 9+)
Identify 3-D shapes, including cubes and other cuboids, from 2-D representations
What a learner can do afterwards
- Identify a cuboid from its net
- Name the 3-D shape shown in an isometric drawing
- Match 2-D representations to the correct 3-D shape
1 · Read
You already know how a net folds up into a solid shape. Now flip that idea around: look at a flat picture and name the 3-D shape it stands for.
A cuboid net is six rectangles joined the right way, like the faces of a box. Each flat piece becomes one face. If all six are same-size squares, that box is a special cuboid called a cube.
Priya looks at a net with one square and four triangles attached to its sides. The triangles meet at a point when folded, so Priya knows this net makes a pyramid, not a cuboid.
An isometric drawing uses slanted lines so a flat picture looks solid, like you are looking at the corner of a real box. Count the flat faces and check the corners to name the shape. A box with six rectangle faces is a cuboid.
A cube has every edge the same length, like a dice. A cuboid can have edges of different lengths, like a shoebox. A pyramid has triangle faces meeting at one point above a flat base. In an isometric drawing, a cube shows equal edges, but a cuboid that is not a cube shows uneven edges.
A flat picture, like a net or an isometric drawing, is a clue that names the 3-D shape hiding inside it.
2 · Watch
Take it off screen
Where it sits
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
18 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.