Topological Basis
A topological basis is a Subset 
of a Set 
in which all other Open Setscan be written as Unions or finite Intersections of . For theReal Numbers, the Set of all Open Intervals is a basis.
- Triangle Transformation Principle
- Triangular Cupola
- Triangular Dipyramid
- Triangular Graph
- Triangular Hebesphenorotunda
- Triangular Matrix
- Triangular Number
- Triangular Orthobicupola
- Triangular Pyramid
- Triangular Square Number
- Triangular Symmetry Group
- Triangulation
- Triaugmented Dodecahedron
- Triaugmented Hexagonal Prism
- Triaugmented Triangular Prism
- Triaugmented Truncated Dodecahedron
- Triaxial Ellipsoid
- Tribar
- Tribonacci Number
- Tribox
- Trichotomy Law
- Tricolorable
- Tricomi Function
- Tricuspoid
- Tricylinder