# Square dipyramid (EntityTopic, 16)

### From Hi.gher. Space

(Redirected from Rotope 18)

A **square dipyramid** is a special case of the pyramid where the base is a square pyramid. It is also a special case of the dipyramid where the base is a square.

## Equations

- Variables:

l⇒ length of each line in the square dipyramid

- The hypervolumes of a square dipyramid are given by:

total edge length = 13l

total surface area = (1 + 6√3) ·l^{2}

surcell volume =^{2√2}∕_{3}·l^{3}

bulk =Unknown

- The realmic cross-sections (
*n*) of a square dipyramid are:

[!x,!y] ⇒ triangular prism

[!z,!w] ⇒ square pyramid

## Net

The net of a square dipyramid is two square pyramids attached at their bases with four tetrahedra each attached to another face of one of the square based pyramids.

No image

## Projection

The parallel projection of a square dipyramid is the following:

Notable Tetrashapes
| |

Regular:
| pyrochoron • aerochoron • geochoron • xylochoron • hydrochoron • cosmochoron |

Powertopes:
| triangular octagoltriate • square octagoltriate • hexagonal octagoltriate • octagonal octagoltriate |

Circular:
| glome • cubinder • duocylinder • spherinder • sphone • cylindrone • dicone • coninder |

Torii:
| tiger • torisphere • spheritorus • torinder • ditorus |

22. 2^{2}Dicone | 23. [11]
^{2}Square dipyramid | 24. 12^{1}Coninder |

List of tapertopes |