The curve traced out by a point on the circumference of a circle rolling round another circle of the same radius. Its equation, in which a is the radius of each circle, may be taken in polar coordinates as . In the figure, OA = 4a and OB = 2a.
The cardioid
- concordant
- concordant age
- Concordat
- Concordia diagram
- Concordia family
- concrete
- concrete dam
- concrete minimum temperature
- concrete number
- concrete universal
- concretion
- concretionary
- concretion, principle of
- concupiscence
- concurrency
- concurrency control
- concurrent
- concurrent assignment
- concurrent DOS
- concurrent programming
- concurrent range zone
- concyclic
- condensate
- condensation
- condensation level