#61 · 3D solids & mensuration · Classes 5–12
3D Solids
Solids have length, width and height. Common ones: cube, cuboid, sphere, cylinder, cone and pyramid.
3D Solids📐 Formula
Euler’s formula for polyhedra: F + V − E = 2
✏️ Worked example
Cube: F = 6, V = 8, E = 12 → 6 + 8 − 12 = 2.
🌍 Where it is used
Packaging, buildings, containers and machine parts.
❓ Quick check
Which solid has no flat faces?