MATHEMATICS LAB · GEOMETRY
Nets of Geometric Solids
Unfold and refold 3D solids to discover how their surfaces become flat nets. Explore faces, fold lines and surface-area formulas, including truncated solids.
The final nets preserve geometric dimensions, including the annular sector of a cone frustum and the trapezoids of a truncated pyramid. Polyhedral faces rotate about their edges; for curved surfaces, the unrolling movement is illustrative, while the final rectangle, circular sectors and annular sector are geometrically accurate. A sphere cannot be unfolded into an exact flat net without distortion.
2. Animated unfolding of the solid
3D solid → flat netCubePress Start unfolding or drag the slider.
Press Start unfolding or move the slider. Drag the graph to rotate the view and use + / − to zoom. At 100%, select Dall'alto to view the true dimensions of the net.
Base Lateral surface area Top base Folds / joints
3. How to read the net
4. Results
Solid and net measurements5. Step-by-step calculations
Formulas and numerical substitutionsWhat you can study
Polyhedra
The faces of cubes, cuboids, prisms, pyramids and pyramid frustums rotate about their edges and flatten without changing shape.
Developable surfaces
The cylinder’s lateral surface becomes a rectangle; the cone unfolds into a circular sector, and the cone frustum into an annular sector. Area is preserved in the final net.
Geometric limitations
Unlike cylinders and cones, a sphere has no exact flat net that preserves all distances.