How to use the 3D Shapes
- Pick a shape. Click a shape in the row along the bottom, or press N and B to step through all twelve.
- Turn it. Drag the shape to look at it from any side; flick it and it keeps spinning. Scroll or pinch to zoom, double-click to go back to the start.
- Count. The card in the corner names the shape, counts its faces, edges and vertices and checks Euler’s formula. Press V to mark the vertices and T to see the hidden edges.
- Unfold it. Press Space or Unfold to open the solid into its net on the floor, and again to fold it up. The slider stops it half way.
Classroom ideas
- Count before you look: hide the card with I, let pairs count faces, edges and vertices, then reveal it. Switch on See-through to settle arguments about the back.
- Which net? Unfold a cube half way with the slider and ask which face will land where. Use A color per face so everyone can follow each square.
- Euler’s detective: record F, V and E for five polyhedra in a table and ask the class to find the rule before you show F + V − E = 2.
- Prism or pyramid? Show the triangular prism and the triangular pyramid side by side on the Classroom Board and list what is the same and what is different.
- Real-world hunt: show a cylinder, then have pupils find three cylinders in the room and sketch their nets.
Keyboard shortcuts
| N / B | Next or previous shape |
| E | Show or hide the edges |
| V | Show or hide the vertices |
| T | See-through mode |
| A | Turn by itself (auto-rotate) |
| I | Show or hide the property card |
| F | Present full screen |
Frequently asked questions
How do you count faces, edges and vertices on curved shapes?
Conventions differ, so the card spells them out. A cylinder has 2 flat faces and 1 curved surface, 2 curved edges and no vertices. A cone has 1 flat face and 1 curved surface, 1 edge and 1 vertex (its apex). A sphere has one curved surface and no edges or vertices. Some schemes count curved surfaces as faces (a cylinder then has 3 faces); use whichever your curriculum uses.
Why doesn’t Euler’s formula appear for the cylinder, cone and sphere?
F + V − E = 2 is a rule about polyhedra: solids made only of flat polygons. Curved shapes do not follow it in a meaningful way, which is a good discussion point in itself.
Which shapes unfold into a net?
All of them except the sphere, which cannot be flattened without stretching. Each solid has many possible nets; the tool shows one that does not overlap, such as the familiar cross for the cube.
Is the triangular pyramid the same as a tetrahedron?
Here it is a regular tetrahedron: four identical equilateral triangles. Any triangular pyramid has 4 faces, 6 edges and 4 vertices, regular or not.
What if my computer cannot show 3D?
The tool switches to flat drawings of the same shapes with the same property card. You can still drag to turn them and show each net.
Updated October 31, 2026 · Free to use in any classroom, no account needed.