17
17 is a Fermat Prime which means that the 17-sided Regular Polygon (the Heptadecagon) isConstructible using Compass and Straightedge (as proved byGauß 
).
References
Lefevre, V. ``Properties of 17.'' http://www.ens-lyon.fr/~vlefevre/d17_eng.html. Shell Centre for Mathematical Education. ``Number 17.'' http://acorn.educ.nottingham.ac.uk/ShellCent/Number/Num17.html.
- Error
- Error-Correcting Code
- Error Curve
- Error Function
- Error Function Distribution
- Error Propagation
- Escher's Map
- Escribed Circle
- Essential Singularity
- Estimate
- Estimator
- Eta Function
- Et-Function
- Ethiopian Multiplication
- Etruscan Venus Surface
- Eubulides Paradox
- Euclidean Algorithm
- Euclidean Construction
- Euclidean Geometry
- Euclidean Group
- Euclidean Metric
- Euclidean Motion
- Euclidean Norm
- Euclidean Number
- Euclidean Plane