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
The lesson
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 net made only of rectangles folds into a cuboid, a box shape. If every rectangle is really a same-size square, 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 cube has every edge the same length, like a dice. A cuboid has edges of different lengths, like a shoebox. A pyramid has triangle faces meeting at one point above a flat base.
A flat picture, like a net or an isometric drawing, is a clue that names the 3-D shape hiding inside it.
Watch it
Where it sits
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
8 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.