#90 · 3D solids & mensuration · Classes 8–12
Geometry (3D)
Solid figures, their cross-sections and symmetry.
Geometry (3D)📐 Formula
Cross-sections: a cube can be cut to give a square, rectangle, triangle or hexagon
✏️ Worked example
A cut through a cube parallel to a face gives a square.
🌍 Where it is used
CT scans, 3D printing and engineering drawings.
❓ Quick check
A sphere cut by a plane always gives a…