2-D faces on 3-D shapes
Identify 2-D shapes on the surface of 3-D shapes (e.g. a circle on a cylinder, a triangle on a pyramid)
What a learner can do afterwards
- Point out a circular face on a cylinder or cone
- Identify triangular faces on a pyramid
- Recognise that the faces of 3-D shapes are 2-D shapes
The lesson
Solid shapes like a cone or a pyramid have flat parts on the outside. Each flat part is called a face. Every face is a 2-D shape you already know, like a circle, a triangle, or a square.
A cone, like an ice-cream cone, also has a flat circle face on the bottom. If you peel the paper off a can and lay it flat, the curved side turns into a rectangle.
A pyramid has triangle faces on its sides. They meet at a point at the top. The bottom face can be a square.
To find a face, run your finger over a flat part of a solid shape until you reach an edge. Then look at the flat shape you traced.
Every face on a solid shape is a flat 2-D shape, like a circle, triangle, or square.
Watch it
Where it sits
Learn first
This opens up
Nothing builds on it yet.
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.