Basic Techniques, DCEL, Plane sweep and Planarity.
Triabgulations, Art-Gallery Theorem, and an O(n log n) algorithm for triangulating a simple polygon.
Point Location among a set of segments.
Properties of Voronoi Diagrams.
We also discussed 2D range trees (from Lecture 5), Interval Trees and Segment trees (see the textbook) and and the basic definition of Quadtrees (see the textbook).