Solid Geometry

The box family: prism anatomy, the cube's √2 and √3 diagonals, and surface & volume you can see face by face.

Height, apothem, slant, edge — the two Pythagorean triangles inside every pyramid, the ⅓ in the volume, and the frustum.

The round solids you can unroll: the cylinder's rectangle label, the cone's pie-slice development, and both volumes.

Every slice a circle (r² = R² − d²), the surface of exactly four great circles, and Archimedes' tombstone 2:3.

Predict any cut, scale with k / k² / k³, glue and drill combined solids — and the five-triangle exam strategy.