Illustration of a octagonal bifrustum created by three parallel planes of octagons with the middle plane…

Illustration of a regular octagon inscribed in a circle. This can also be described as a circle circumscribed…

An illustration showing how to construct a regular octagon from a square by cutting off the corners…

Illustration used to show how to inscribe a regular octagon in a given circle.

Illustration of a regular octagon circumscribed about a square. This could also be described as a square…

An illustration showing how to construct an octagon on a given line. "Prolong AB to C. With B as center…

Illustration showing the intersection of a plane with an octagonal prism.

Illustration of a figure that is made up of 4 octagons with 5 squares (diamonds).