Linkage
Sylvester, 
Kempe and Cayley developed the geometry associated with the theory of linkages in the1870s. Kempe proved that every finite segment of an algebraic curve can be generated by a linkage in the manner ofWatt's Curve.
References
Cundy, H. and Rollett, A. Mathematical Models, 3rd ed. Stradbroke, England: Tarquin Pub., 1989.
- Carathéodory Derivative
- Carathéodory's Fundamental Theorem
- Cardano's Formula
- Cardinality
- Cardinal Number
- Cardioid
- Cardioid Caustic
- Cardioid Evolute
- Cardioid Inverse Curve
- Cardioid Involute
- Cardioid Pedal Curve
- Cards
- Carleman's Inequality
- Carlson-Levin Constant
- Carlson's Theorem
- Carlyle Circle
- Carmichael Condition
- Carmichael Function
- Carmichael Number
- Carmichael's Conjecture
- Carmichael Sequence
- Carmichael's Theorem
- Carmichael's Totient Function Conjecture
- Carnot's Polygon Theorem
- Carnot's Theorem