Illustration of a pentagonal antiprism. An antiprism is formed by having two parallel congruent bases connected by an alternating band of triangles. The bases in this illustration are pentagons.

Pentagonal Antiprism

Illustration of a pentagonal antiprism. An antiprism is formed by having two parallel congruent bases…

Illustration of a pentagonal antiprism. An antiprism is formed by having two parallel congruent bases connected by an alternating band of triangles. The bases in this illustration are pentagons.

Pentagonal Antiprism

Illustration of a pentagonal antiprism. An antiprism is formed by having two parallel congruent bases…

Illustration of a pentagonal antiprism. An antiprism is formed by having two parallel congruent bases connected by an alternating band of triangles. The bases in this illustration are pentagons.

Pentagonal Antiprism

Illustration of a pentagonal antiprism. An antiprism is formed by having two parallel congruent bases…

Illustration of a pentagonal antiprism. An antiprism is formed by having two parallel congruent bases connected by an alternating band of triangles. The bases in this illustration are pentagons.

Pentagonal Antiprism

Illustration of a pentagonal antiprism. An antiprism is formed by having two parallel congruent bases…

Illustration of a skewed (non-right) pentagonal antiprism. An antiprism is formed by having two parallel congruent bases connected by an alternating band of triangles. The bases in this illustration are pentagons.

Skewed Pentagonal Antiprism

Illustration of a skewed (non-right) pentagonal antiprism. An antiprism is formed by having two parallel…

Illustration of a pentagonal bipyramid. A bipyramid, or dipyramid, is formed by joining two congruent pyramids at their bases. The bases in this illustration are pentagons.

Pentagonal Bipyramid

Illustration of a pentagonal bipyramid. A bipyramid, or dipyramid, is formed by joining two congruent…

Illustration of a pentagonal bipyramid. A bipyramid, or dipyramid, is formed by joining two congruent pyramids at their bases. The bases in this illustration are pentagons.

Pentagonal Bipyramid

Illustration of a pentagonal bipyramid. A bipyramid, or dipyramid, is formed by joining two congruent…

Illustration of pentagon inscribed in circle. Or, circle circumscribed about pentagon.

Pentagon Inscribed in Circle

Illustration of pentagon inscribed in circle. Or, circle circumscribed about pentagon.

Illustration of polygon circumscribed about circle. Or, circle inscribed in the polygon.

Polygon Circumscribed About Circle

Illustration of polygon circumscribed about circle. Or, circle inscribed in the polygon.

Illustration of polygon inscribed in circle. Or, circle circumscribed about the polygon.

Polygon Inscribed in Circle

Illustration of polygon inscribed in circle. Or, circle circumscribed about the polygon.

Right circular cylinder inscribed in a pentagonal prism. Or, Pentagonal prism circumscribed about a cylinder.

Cylinder Inscribed in Pentagonal Prism

Right circular cylinder inscribed in a pentagonal prism. Or, Pentagonal prism circumscribed about a…

Illustration of a pentagonal prism inscribed in a cylinder.

Prism inscribed in Cylinder

Illustration of a pentagonal prism inscribed in a cylinder.

2 pentagons that are similar figures

Similar Figures

2 pentagons that are similar figures

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

Flashcard of a polygon with five equal sides

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

A flashcard featuring an illustration of a Pyramid with a Pentagonal Base

Flashcard of a Pyramid with a Pentagonal Base

A flashcard featuring an illustration of a Pyramid with a Pentagonal Base

Illustration of regular hexagon and triangle inscribed in circle.

Hexagon Inscribed in Circle by Construction

Illustration of regular hexagon and triangle inscribed in circle.

Illustration of an icosahedron.

Icosahedron

Illustration of an icosahedron.

Illustration of the bottom part of an icosahedron. The base consists of a regular pyramid, upon which equilateral triangles are inserted to form the next section of the icosahedron.

Part of an Icosahedron

Illustration of the bottom part of an icosahedron. The base consists of a regular pyramid, upon which…

Illustration of the steps to a construction of an icosahedron. The base consists of a regular pyramid, upon which equilateral triangles are inserted to form the next section of the icosahedron, followed by another pyramid.

Partial Construction of an Icosahedron

Illustration of the steps to a construction of an icosahedron. The base consists of a regular pyramid,…

"A polygon of five sides." -—Hallock 1905

Pentagon

"A polygon of five sides." -—Hallock 1905

An illustration showing how to construct a pentagon on a given line without resort to its center. "From B erect Bo perpendicular to and equal to AB; with C as center and Co as radius, draw the arc Do, then AD is the diagonal of the pentagon. With AD as radius and A as center, draw the arc DE; and with E as center and AB as radius, finish the cross E, and thus complete the pentagon."

Construction Of A Pentagon On A Line

An illustration showing how to construct a pentagon on a given line without resort to its center. "From…

Regular pentagon inscribed in a circle, circumscribed about a circle.

Pentagon Inscribed & Circumscribed in Circles

Regular pentagon inscribed in a circle, circumscribed about a circle.

Illustration of a how to construct a pentagon similar to two given pentagons.

Pentagon Constructed to be Similar to Given Pentagons

Illustration of a how to construct a pentagon similar to two given pentagons.

Illustration used to construct a regular pentagon on a given line.

Construction of Regular Pentagon

Illustration used to construct a regular pentagon on a given line.

Illustration of a cyclic pentagon, a pentagon inscribed in a circle. This can also be described as a circle circumscribed about a pentagon. In this illustration, the pentagon is not regular (the lengths of the sides are not equal).

Cyclic Pentagon

Illustration of a cyclic pentagon, a pentagon inscribed in a circle. This can also be described as a…

Illustration of pentagon inscribed in circle. Or, circle circumscribed about pentagon. Construction lines shown.

Pentagon Inscribed in Circle by Construction

Illustration of pentagon inscribed in circle. Or, circle circumscribed about pentagon. Construction…

"An involute is a curve generated by unwrapping an inflexible chord from around a polygon. Thus the involute of any polygon may be drawn by extending its sides, and with the corners of the polygon as successive centers drawing the tangent arcs." —French, 1911

Involute of Pentagon

"An involute is a curve generated by unwrapping an inflexible chord from around a polygon. Thus the…

Illustration of an irregular pentagon. This is also an example of a concave polygon with symmetry.

Irregular Concave Pentagon

Illustration of an irregular pentagon. This is also an example of a concave polygon with symmetry.

Illustration of an irregular concave pentagon.

Irregular Concave Pentagon

Illustration of an irregular concave pentagon.

Illustration of an irregular pentagon. This is also an example of a convex polygon with symmetry.

Irregular Convex Pentagon

Illustration of an irregular pentagon. This is also an example of a convex polygon with symmetry.

Illustration of an irregular pentagon. This is also an example of a convex polygon with symmetry.

Irregular Convex Pentagon

Illustration of an irregular pentagon. This is also an example of a convex polygon with symmetry.

Illustration of an irregular convex pentagon.

Irregular Convex Pentagon

Illustration of an irregular convex pentagon.

Illustration showing a circle inscribed in a regular pentagon. Or, a regular pentagon circumscribed about a circle.

Regular Pentagon With Circle Inscribed

Illustration showing a circle inscribed in a regular pentagon. Or, a regular pentagon circumscribed…

Pentagon with dimensions labeled. Pentagon can be used to calculate area by calculating individual triangles and finding the sum of the areas.

Pentagon With Triangular Sections For Area

Pentagon with dimensions labeled. Pentagon can be used to calculate area by calculating individual triangles…

"This is bounded by twelve pentagonal faces, but these are not regular pentagons, and the angles over the three sets of different edges are different. The regular dodecahedron of geometry, contained by twelve regular pentagons, is not a possible form in crystals." -The Encyclopedia Britannica 1910

Pentagonal Dodecahedron

"This is bounded by twelve pentagonal faces, but these are not regular pentagons, and the angles over…

Illustration of a frustum of a pentagonal pyramid (including cross-section).

Frustum of Pentagonal Pyramid

Illustration of a frustum of a pentagonal pyramid (including cross-section).

Illustration of a right pentagonal pyramid that has been cut by a plane parallel to the base. The top section has been removed and the remaining section is known as the frustum of the pyramid. The hidden edges are shown in this illustration.

Frustum Of A Pentagonal Pyramid

Illustration of a right pentagonal pyramid that has been cut by a plane parallel to the base. The top…

Illustration of a hollow pentagonal pyramid that has been cut by a plane parallel to the base. The top section has been removed and the remaining section has been turned upside down. It is known as the frustum of the pyramid.

Frustum Of A Pentagonal Pyramid

Illustration of a hollow pentagonal pyramid that has been cut by a plane parallel to the base. The top…

Illustration of a right pentagonal pyramid, with a height much larger than the edge lengths of the base, that has been cut by a plane parallel to the base. The top section has been removed and the remaining section is known as the frustum of the pyramid. The hidden edges are shown in this illustration.

Frustum Of A Pentagonal Pyramid

Illustration of a right pentagonal pyramid, with a height much larger than the edge lengths of the base,…

Illustration of a right pentagonal pyramid, with a height smaller than the edge lengths of the base, that has been cut by a plane parallel to the base. The top section has been removed and the remaining section is known as the frustum of the pyramid. The hidden edges are shown in this illustration.

Frustum Of A Pentagonal Pyramid

Illustration of a right pentagonal pyramid, with a height smaller than the edge lengths of the base,…

Illustration of a hollow pentagonal pyramid that has been cut by a plane parallel to the base. The top section has been removed and the remaining section has been turned upside down. It is known as the frustum of the pyramid. The hidden edges are shown in this illustration.

Frustum Of A Pentagonal Pyramid

Illustration of a hollow pentagonal pyramid that has been cut by a plane parallel to the base. The top…

Illustration of a skewed pentagonal pyramid that has been cut by a plane parallel to the base. The top section has been removed and the remaining section is known as the frustum of the pyramid. The hidden edges are shown in this illustration.

Frustum Of A Skewed Pentagonal Pyramid

Illustration of a skewed pentagonal pyramid that has been cut by a plane parallel to the base. The top…

Illustration of 2 concentric pentagons.

2 Concentric Pentagons

Illustration of 2 concentric pentagons.

Illustration of 2 concentric pentagons.

2 Concentric Pentagons

Illustration of 2 concentric pentagons.

Illustration of 2 regular congruent pentagons that have the same center. One pentagon has been rotated 36° in relation to the other.

2 Congruent Rotated Pentagons

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

Illustration of 3 concentric pentagons that are equally spaced.

3 Concentric Pentagons

Illustration of 3 concentric pentagons that are equally spaced.

Illustration of 4 concentric pentagons that are equally spaced.

4 Concentric Pentagons

Illustration of 4 concentric pentagons that are equally spaced.

Illustration of 4 regular congruent pentagons that have the same center. Each pentagon has been rotated 18° in relation to the one next to it.

4 Congruent Rotated Pentagons

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 9° in relation to the one next to it.

8 Congruent Rotated Pentagons

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

Illustration showing two congruent pentagons.

Congruent Pentagons

Illustration showing two congruent pentagons.

Illustration of 2 similar pentagons.

Similar Pentagons

Illustration of 2 similar pentagons.

Illustration of 2 similar pentagons.

Similar Pentagons

Illustration of 2 similar pentagons.

Polygon consisting of 5 sides

5-sided Polygon

Polygon consisting of 5 sides

Illustration of crossed polygon. This is not generally considered to be a real polygon.

Crossed Polygon

Illustration of crossed polygon. This is not generally considered to be a real polygon.

1/5 of a 5 sided polygon

Fractions of 5-sided Polygon

1/5 of a 5 sided polygon

2/5 of a 5 sided polygon

Fractions of 5-sided Polygon

2/5 of a 5 sided polygon

3/5 of a 5 sided polygon

Fractions of 5-sided Polygon

3/5 of a 5 sided polygon

4/5 of a 5 sided polygon

Fractions of 5-sided Polygon

4/5 of a 5 sided polygon

5/5 of a 5 sided polygon

Fractions of 5-sided Polygon

5/5 of a 5 sided polygon

Illustration of a polygon with exterior angles drawn.

Exterior Angles of Polygons

Illustration of a polygon with exterior angles drawn.