Illustration showing a circle with equilateral triangles and another circle within.

Illustration of a regular nonagon inscribed in a circle. This could also be described as a circle circumscribed…

A 5-point star made from a non-regular concave decagon in which all sides are equal in length.

Illustration of 12 equilateral triangles inscribed in an equilateral dodecagon. Each vertex of the dodecagon…

Illustration of 3 squares inscribed in an regular dodecagon. Each vertex of the dodecagon is also a…

Illustration of a regular hexagon and an equilateral triangle inscribed in a regular dodecagon. This…

Illustration of a regular hexagon inscribed in a regular dodecagon. This could also be described as…

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

Illustration of a square inscribed in an regular dodecagon. This could also be described as a regular…

Illustration of 2 squares; one inscribed in a regular dodecagon and the other circumscribed about the…

Illustration of an equilateral triangle inscribed in an equilateral dodecagon. This could also be described…

A, B, and C show three types of triangular prisms: right, isosceles, and equilateral. When put together…

"Equilateral pointed arches, described from two centers, the radius being the whole width of the arch."…

Illustration of an equilateral triangle that shows both the centroid (where the medians of the sides…

Illustration of 10 congruent equilateral triangles that have the same center. Each triangle has been…

Illustration of 10 congruent equilateral triangles that have the same center. Each triangle has been…

Illustration of 20 congruent equilateral triangles that have the same center. Each triangle has been…

Illustration of 3 concentric equilateral triangles that are equally spaced.

Illustration of 4 concentric equilateral triangles that are equally spaced.

Illustration of 5 congruent equilateral triangles that have the same center. Each triangle has been…

A flashcard featuring an illustration of a polygon with three equal sides

Illustration of a regular hexagon with each side divided into thirds by line segments extended to the…

Illustration of 2 regular concentric hexagons with 6 congruent circles placed between the hexagons so…

Illustration of a circle inscribed in a regular nonagon. This could also be described as a regular nonagon…

Illustration of a regular nonagon. A nonagon is a closed geometric figure with 9 sides. A regular nonagon…

Illustration of an equilateral triangle inscribed in a regular nonagon. This could also be described…

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

Illustration of 2 regular congruent pentagons that have the same center. One pentagon has been rotated…

Illustration of 4 regular congruent pentagons that have the same center. Each pentagon has been rotated…

Illustration of 8 regular congruent pentagons that have the same center. Each pentagon has been rotated…

Illustration of a two polygons. Polygons may be mutually equiangular without being mutually equilateral.