Square Pyramid
Get Square Pyramid essential facts below. View Videos or join the Square Pyramid discussion. Add Square Pyramid to your PopFlock.com topic list for future reference or share this resource on social media.
Square Pyramid
Square pyramid
Square pyramid.png
TypeJohnson
J92 - J1 - J2
Faces4 triangles
1 square
Edges8
Vertices5
Vertex configuration4(32.4)
(34)
Schläfli symbol( ) ? {4}
Symmetry groupC4v, [4], (*44)
Rotation groupC4, [4]+, (44)
Dual polyhedronself
Propertiesconvex
Net
Square pyramid net.svg
3D model of a square pyramid

In geometry, a square pyramid is a pyramid having a square base. If the apex is perpendicularly above the center of the square, it is a right square pyramid, and has C4v symmetry. If all edges are equal, it is an equilateral square pyramid,[1] the Johnson solid J1.

General square pyramid

A possibly oblique square pyramid with base length l and perpendicular height h has volume:

.

Right square pyramid

In a right square pyramid, all the lateral edges have the same length, and the sides other than the base are congruent isosceles triangles.

A right square pyramid with base length l and height h has surface area and volume:

.

The lateral edge length is:

,

and the slant height is:

.

The dihedral angles are:

between the base and a side: ;
between two sides: .

Equilateral square pyramid, Johnson solid J1

If all the edges have the same length, then the sides are equilateral triangles, and the pyramid is an equilateral square pyramid, Johnson solid J1.

The Johnson square pyramid can be characterized by a single edge length parameter l.

The height h (from the midpoint of the square to the apex), the surface area A (including all five faces), and the volume V of an equilateral square pyramid are:

The dihedral angles of an equilateral square pyramid are:

  • Between the base and a side:
  • Between two (adjacent) sides:

Graph

A square pyramid can be represented by the Wheel graph W5.

Related polyhedra and honeycombs

Regular pyramids
Digonal Triangular Square Pentagonal Hexagonal Heptagonal Octagonal Enneagonal Decagonal...
Improper Regular Equilateral Isosceles
Biangular pyramid1.png Tetrahedron.svg Square pyramid.png Pentagonal pyramid.png Hexagonal pyramid.png Heptagonal pyramid1.png Octagonal pyramid1.png Enneagonal pyramid1.png Decagonal pyramid1.png
Spherical digonal pyramid.png Spherical trigonal pyramid.png Spherical square pyramid.png Spherical pentagonal pyramid.png Spherical hexagonal pyramid.png Spherical heptagonal pyramid.png Spherical octagonal pyramid.png Spherical enneagonal pyramid.png Spherical decagonal pyramid.png
Square bipyramid.png Tetrakishexahedron.jpg Usech kvadrat piramid.png
A regular octahedron can be considered a square bipyramid, i.e. two Johnson square pyramids connected base-to-base. The tetrakis hexahedron can be constructed from a cube with short square pyramids added to each face. Square frustum is a square pyramid with the apex truncated.

Square pyramids fill space with tetrahedra, truncated cubes or cuboctahedra.[2]

Dual polyhedron

The square pyramid is topologically a self-dual polyhedron. The dual edge lengths are different due to the polar reciprocation.

Dual Square pyramid Net of dual
Dual Square Pyramid New.png Dual Square Pyramid Net New.png

References

External links

  • Eric W. Weisstein, Square pyramid (Johnson solid) at MathWorld.
  • Weisstein, Eric W. "Wheel graph". MathWorld.
  • Square Pyramid -- Interactive Polyhedron Model
  • Virtual Reality Polyhedra www.georgehart.com: The Encyclopedia of Polyhedra (VRML model)

  This article uses material from the Wikipedia page available here. It is released under the Creative Commons Attribution-Share-Alike License 3.0.

Square_pyramid
 



 



 
Music Scenes