Octagon construction and formulas

Construction of a Regular Octagon

Octagonal Prism - Everything you need for the Elementary Math Student

What is Octagon? Definition, Formula, Properties, Examples

Octagonal Prisms: Paper Models, Surface Area, Volume Formulas and Nets – Tim's Printables

Regular Octagon -- from Wolfram MathWorld

Octagon - Wikipedia

Octagon construction and formulas

Octagon - Definition, Formula, Examples

Octagon Formula: Types, Properties, Derivation