Nonagram
The Star Figure 
composed of three Equilateral Triangles rotated at angles 0°, 40°, and 80°. It has been called the Star of Goliath by analogy withthe Star of David (Hexagram).
- Star Number
- Star of David
- Star of Goliath
- Star of Lakshmi
- Star Polygon
- Star Polyhedron
- Starr Rose
- State Space
- Stationary Point
- Stationary Tangent
- Stationary Value
- Statistic
- Statistical Test
- Statistics
- Staudt-Clausen Theorem
- Steenrod Algebra
- Steenrod-Eilenberg Axioms
- Steenrod's Realization Problem
- Steepest Descent Method
- Steffensen's Inequality
- Steffenson's Formula
- Steinbach Screw
- Steiner Chain
- Steiner Construction
- Steinerian Curve