--- title: "2-D faces on 3-D shapes" description: "Identify 2-D shapes on the surface of 3-D shapes (e.g. a circle on a cylinder, a triangle on a pyramid)" canonical: https://lightmysky.com/learn/mathematics/2-d-faces-on-3-d-shapes-mt_UooUHC_V7U source: https://lightmysky.com/learn/mathematics/2-d-faces-on-3-d-shapes-mt_UooUHC_V7U.md retrieved: 2026-11-12 --- > **Agent view.** This is the Markdown twin of the page, for tools and assistants. > When to use this site, and the call that answers each job: https://lightmysky.com/agent-instructions.md > API description (OpenAPI 3.1): https://lightmysky.com/openapi.json · Authentication: https://lightmysky.com/auth.md > Pricing: https://lightmysky.com/pricing.md · Catalog: https://lightmysky.com/llms.txt · Full catalog: https://lightmysky.com/llms-full.txt > Every machine-readable file on this domain: https://lightmysky.com/.well-known/ai-catalog.json > Ask for Markdown with `Accept: text/markdown`, a `.md` address, or `?mode=agent`. # 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) Subject: Mathematics · Area: Geometry · Ages 6 to 7 Page: https://lightmysky.com/learn/mathematics/2-d-faces-on-3-d-shapes-mt_UooUHC_V7U ## Ready when they can - Identify and count circular flat faces on cones and cylinders, including faces left uncovered - Identify triangular faces on a pyramid - Recognise that the faces of 3-D shapes are 2-D shapes - Identify pyramid bases and count or compare the faces of square-based and triangular pyramids - Count cube and cuboid faces, including faces hidden from view - Recognise that every cube face has the same size and shape ## Lesson: Flat shapes on solid shapes You have met flat shapes and solid shapes. Flat shapes are 2-D. Solids are 3-D. A face is a flat part on the outside of a solid. In this lesson, a curved surface is not a face. A sphere, like a ball, curves all over and has no flat faces. A cylinder has two flat faces, one at each end. Both are circles. The surface around its side is curved. If you cover one circular end, the other circular end is still uncovered. A solid model cone has one flat circular face, called its base. Its pointed tip is not a face. Turning the cone does not change its base into a different shape. A cone has one circular face; a cylinder has two. **Example.** A rectangular paper label can wrap around a can's curved side. Take the label off and lay it flat. It has four straight sides and four square corners. Opposite sides match in length. The label is a rectangle. The wrapped side of the can is curved, not a flat face. A pyramid's side faces are triangles. Each triangle has three straight sides. The side faces meet at a point, which is not a face. A square-based pyramid has a square base and four triangular sides: five faces. A triangular pyramid has a triangular base and three triangular sides: four faces. A cube has six square faces, all the same size and shape. A square has four equal straight sides and four square corners. To count the cube's faces, count top and bottom, front and back, then left and right. Those three pairs make six. A cuboid is a box shape with six rectangular faces. Its top and bottom make one pair. Its front and back make another. Its left and right make the last pair. Each face is flat, although the whole box is solid. A drawing can hide faces at the back or underneath a solid. Turn a model to find those faces too. Count each face once. Turning the model changes your view, but it does not change the shapes or number of its faces. *(drawing: Trace four equal straight sides and four square corners.)* **Recap.** Every face on a solid shape is a flat 2-D shape, like a circle, triangle, or square. *Lesson, practice questions and flashcards written for this dataset.* ## Practice 18 questions on this page, each with its working shown. ## Needs first - [Flat vs Solid Shapes](https://lightmysky.com/learn/mathematics/flat-vs-solid-shapes-mt_mnEVZNkX3p) ## Opens up - [Nets of 3-D shapes](https://lightmysky.com/learn/mathematics/nets-of-3-d-shapes-mt_vnJEztczji)