51Mxx Real and complex geometry
- 51M04 Elementary problems in Euclidean geometries
- 51M05 Euclidean geometries (general) and generalizations
- 51M09 Elementary problems in hyperbolic and elliptic geometries
- 51M10 Hyperbolic and elliptic geometries (general) and generalizations
- 51M15 Geometric constructions
- 51M16 Inequalities and extremum problems (For convex problems, see 52A40)
- 51M20 Polyhedra and polytopes; regular figures, division of spaces [See also 51F15] (2)
- 51M25 Length, area and volume [See also 26B15]
- 51M30 Line geometries and their generalizations [See also 53A25]
- 51M35 Synthetic treatment of fundamental manifolds in projective geometries (Grassmannians, Veronesians and their generalizations) [See also 14M15]
- 51M99 None of the above, but in this section