Poncelet's Closure Theorem
If an 
-sided Poncelet Transverse constructed for two given Conic Sections is closed for one point oforigin, it is closed for any position of the point of origin. Specifically, given one Ellipse inside another, ifthere exists one Circuminscribed (simultaneously inscribed in the outer and circumscribed on the inner) -gon, then anypoint on the boundary of the outer Ellipse is the Vertex of some Circuminscribed -gon.
References
Dörrie, H. 100 Great Problems of Elementary Mathematics: Their History and Solutions. New York: Dover, p. 193, 1965.
- Brun's Sum
- Brun's Theorem
- Brute Force Factorization
- B-Spline
- B-Tree
- Bubble
- Buchberger's Algorithm
- Buckminster Fuller Dome
- Buffon-Laplace Needle Problem
- Buffon's Needle Problem
- Bulirsch-Stoer Algorithm
- Bullet Nose
- Bumping Algorithm
- Bundle
- Burau Representation
- Burkhardt Quartic
- Burnside Problem
- Burnside's Conjecture
- Burnside's Lemma
- Busemann-Petty Problem
- Busy Beaver
- Small Multiple Method
- Small Number
- Small Retrosnub Icosicosidodecahedron
- Small Rhombicosidodecahedron