Concepts4

3D geometry relies on a small toolkit: vectors, dot products, cross products, and planes; mastering these unlocks most 3D problem-solving.

Rotating calipers is a geometric two-pointer technique that sweeps two (or more) parallel support lines around a convex polygon.

A line can be represented by two points, a point with a direction vector, or the general form ax + by + c = 0, and these forms are interconvertible.

A 2D point can be treated as a vector from the origin, so vector math (addition, scaling, dot, cross) applies directly to points.