Flag
A collection of Faces of an 
-D Polytope or Simplicial Complex, one of each Dimension 0, 1, ..., 
, which all have a common nonempty Intersection. In normal 3-D, theflag consists of a half-plane, its bounding Ray, and the Ray's endpoint.
- Cyclide
- Cyclidic Coordinates
- Cycloid
- Cycloid Evolute
- Cycloid Involute
- Cycloid Radial Curve
- Cyclomatic Number
- Cyclotomic Equation
- Cyclotomic Factorization
- Cyclotomic Field
- Cyclotomic Integer
- Cyclotomic Invariant
- Cyclotomic Number
- Cyclotomic Polynomial
- Cylinder
- Cylinder Cutting
- Cylinder-Cylinder Intersection
- Cylinder Function
- Cylinder-Sphere Intersection
- Cylindrical Coordinates
- Cylindrical Equal-Area Projection
- Cylindrical Equidistant Projection
- Cylindrical Function
- Cylindrical Harmonics
- Cylindrical Hoof