Nets of 3-D Shapes
Identify, draw, and interpret nets of common 3-D shapes — cubes, cuboids, triangular prisms, and square-based pyramids — by predicting which 3-D shape a given flat arrangement of faces will fold into, checking whether a net will close completely, and sketching a net from a description or 3-D model; understand the relationship between the number of faces and the structure of the net
What a learner can do afterwards
- Draw the net of a cube, cuboid, or triangular prism and fold it mentally to identify which faces connect
- Build a 3-D shape from its net and check that all faces, edges, and vertices match
- Identify which of several given nets will fold into a specific 3-D shape and explain why the others won't
The lesson
A net is a flat pattern that folds up into a 3-D shape. Every face of the shape appears once in the net, laid out flat and joined at the edges. Cut open a cardboard box along its edges and flatten it, and you get that box's net.
Take a cereal box apart carefully along its glued seams and press it flat. You'll see six rectangles joined together. That flat pattern is the cuboid's net. Fold along the same lines and the box closes back up, with no gaps and no overlaps.
Before you trust a net, count its faces. A cube needs six squares. A triangular prism needs two triangles and three rectangles. A square-based pyramid needs one square and four triangles. Wrong count, and the net can't close into that shape.
A net is the flat, unfolded layout of a 3-D shape that closes with no gaps when every face is folded into place.
Watch it
Where it sits
Learn first
Nothing; this is a starting point.
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.