🎓 Deeper Dive — Adults

2D shapes (polygons) are classified by sides: triangle (3), quadrilateral (4), pentagon (5), hexagon (6) … n-gon (n).

Angle sum rule: interior angles of any polygon = (n−2) × 180°. So a hexagon has 720°. Each angle in a regular n-gon = (n−2)×180/n.

3D shapes: sphere, cube, cylinder, cone, pyramid. Faces F + Vertices V = Edges E + 2 (Euler's formula for convex polyhedra).