Illustration of an octagon with symmetry with respect to two axes perpendicular to each other. It is…
Illustrations of a circle with arc, chord, inscribed angle, and circumscribed about a polygon.
Illustrations of a circle with a circumscribed polygon. Or, a circle inscribed in an octagon.
Illustration of a circle with a polygon (octagon) and square inscribed.
An illustration of both sides of a U.S. Half Dollar that can be cutout and folded.