257-gon
257 is a Fermat Prime, and the 257-gon is therefore a Constructible Polygon using Compass andGauß. 
An illustration of the 257-gon is not included here, sinceits 257 segments so closely resemble a Circle. Richelot and Schwendenwein found constructions for the 257-gon in1832 (Coxeter 1969). De Temple (1991) gives a construction using 150 Circles (24 of which areCarlyle Circles) which has Geometrography symbol 
andSimplicity 566.
References
Coxeter, H. S. M. Introduction to Geometry, 2nd ed. New York: Wiley, 1969. De Temple, D. W. ``Carlyle Circles and the Lemoine Simplicity of Polygonal Constructions.'' Amer. Math. Monthly 98, 97-108, 1991. Dixon, R. Mathographics. New York: Dover, p. 53, 1991. Rademacher, H. Lectures on Elementary Number Theory. New York: Blaisdell, 1964.
- Biprism
- Bipyramid
- Biquadratefree
- Biquadratic Equation
- Biquadratic Number
- Biquadratic Reciprocity Theorem
- Biquaternion
- Birational Transformation
- Birch Conjecture
- Birch-Swinnerton-Dyer Conjecture
- Birkhoff's Ergodic Theorem
- Birotunda
- Birthday Attack
- Birthday Problem
- Bisected Perimeter Point
- Bisection Procedure
- Bisector
- Bishop's Inequality
- Bishops Problem
- Bislit Cube
- Bispherical Coordinates
- Bitangent
- Bit Complexity
- Bivariate Distribution
- Bivector