Illustration showing a circle with an inscribed and circumscribed quadrilateral.

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

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…

Numbered boxes that are used for fractions. Fraction boxes within can be referred by the letter corners.…

Illustration showing the construction of a golden rectangle. Beginning with a unit square, a line is…

Illustration of parallelogram AEFC drawn two different ways with base b and altitude/height a used to…

Illustration of a decagonal prism with regular decagons for bases and rectangular faces. The hidden…

Illustration of a right decagonal prism with regular decagons for bases and rectangular faces.

Illustration of a right decagonal prism with regular decagons for bases and rectangular faces. The prism…

Illustration of a swimming pool and water hose that is in the shape of a hollow regular decagonal prism…

Illustration of a hollow right heptagonal/septagonal prism with regular heptagons/septagons for bases…

Illustration of a regular right heptagonal/septagonal prism with regular heptagons/septagons for bases…

Illustration of a right heptagonal/septagonal prism with regular heptagons/septagons for bases and rectangular…

Illustration of a right heptagonal/septagonal prism with regular heptagons/septagons for bases and rectangular…

Illustration of a right hexagonal prism with a height less than the length of the edge of the hexagon.

Illustration of a right hexagonal prism with a height greater than the length of the edge of the hexagon.

Illustration of a right hexagonal prism with hexagons for bases and square faces. The hidden edges are…

Illustration of a right hexagonal prism with hexagons for bases and rectangular faces. The height of…

Illustration of a right nonagonal prism with regular nonagons for bases and rectangular faces. The hidden…

Illustration of a right nonagonal prism with regular nonagons for bases and rectangular faces. The height…

Illustration of a right octagonal prism with regular octagons for bases and rectangular faces. The hidden…

Illustration of a right octagonal prism with regular octagons for bases and rectangular faces. The height…

Illustration of a right octagonal prism with octagons for bases and rectangular faces. The height of…

Illustration of a right octagonal prism, with octagons for bases and rectangular faces, that is resting…

Illustration of a right pentagonal prism with regular pentagons for bases and rectangular faces. The…

Illustration of a right pentagonal prism with regular pentagons for bases and rectangular faces. The…

Illustration of a right pentagonal prism with regular pentagons for bases and rectangular faces. The…

Illustration of a right rectangular prism with the height greater than the length and width. The bases…

Illustration of a right rectangular prism. The bases are congruent rectangles and the opposite faces…

Illustration of a right rectangular prism that is viewed at an angle. The bases are congruent rectangles…

Illustration of a right rectangular prism that is viewed at an angle. The bases are congruent rectangles…

Illustration of a right rectangular prism. The bases are congruent rectangles and the opposite faces…

Illustration of a right rectangular prism with the height greater than the length and width. The bases…

Illustration of a non-regular decagonal prism in the shape of a star. Then ends/bases are made of star-shaped…

Illustration of a non-regular decagonal prism in the shape of a star. Then ends/bases are made of star-shaped…

Side view of a non-regular decagonal prism in the shape of a star. Then ends/bases are made of star-shaped…

Illustration of 2 right octagonal prisms with congruent bases, but different heights. The height of…

Illustration of 2 right rectangular prisms. The bases are congruent, but the height of the smaller prism…

Illustration of 2 right rectangular prisms. The bases are congruent, but the height of the smaller prism…

Illustration of 2 Similar right octagonal prisms. The height and length of the edges of the smaller…

Illustration of 4 congruent rectangular prisms placed in the shape of a square. They are arranged to…

Illustration of 2 similar right decagonal prisms. Both have regular decagons for bases and rectangular…

Illustration of 2 similar right heptagonal/septagonal prisms. Both have regular heptagons/septagons…

Illustration of 2 similar right hexagonal prisms. The height of the prism and length of the side of…

Illustration of 2 similar right hexagonal prisms. The height of the prism and length of the side of…

Illustration of a non-right, or skewed, rectangular pyramid with hidden edges shown. The base is a rectangle…

Illustration of a circle inside of a rectangle. The two figures have the same center.

Illustration to show that if the diagonals of a parallelogram are equal, the figure is a rectangle.