Lines and distances
Slope, distance, midpoint
Distance from a point to a line
Conic sections
Circles, parabolas, ellipses, hyperbolas
Foci, directrix, and eccentricity
Areas and transformations
Shoelace formula
Reflections, rotations, and dilations
Vectors and matrices (occasional)
Dot product and basic vector geometry
Determinants for area
Coordinate bashing as a solution strategy