Lituus Inverse Curve
The Inverse Curve of the Lituus is an Archimedean Spiral with 
, which is Fermat's Spiral.
- Stochastic
- Stochastic Calculus of Variations
- Stochastic Group
- Stochastic Matrix
- Stochastic Process
- Stochastic Resonance
- Stokes Phenomenon
- Stokes' Theorem
- Stolarsky Array
- Stolarsky-Harborth Constant
- Stolarsky's Inequality
- Stomachion
- Stone Space
- Stone-von Neumann Theorem
- Stopper Knot
- Straight Angle
- Straightedge
- Straight Line
- Straight Polyomino
- Strange Attractor
- Strange Loop
- Strangers
- Strassen Formulas
- Strassman's Theorem
- Strassnitzky's Formula