Cubic pyramid (EntityTopic, 23)
From Hi.gher. Space
The cubic pyramid is a CRF polychoron among Klitzing's list of segmentochora (K4.26). It is bounded by its cubical base and 6 square pyramidal sides.
Dichoral angles
- Between cube and square pyramid: 45° (exact)
- Between two adjacent square pyramids: 180° - acos(1/3) ≈ 109.4712206345°
Equations
- Variables:
l ⇒ length of edges of the cubic pyramid
- The hypervolumes of a cubic pyramid are given by:
total edge length = 20l
total surface area = (6 + 3√3) · l2
surcell volume = (1 + √2) · l3
bulk = 1∕8 · l4
- The realmic cross-sections (n) of a cubic pyramid are:
[!x,!y,!z] ⇒ square pyramid
[!w] ⇒ cube
Net
The net of a cubic pyramid is a cube surrounded by six square pyramids.
Coordinates
The coordinates of a cubic pyramid with side 2 are:
(±1, ±1, ±1, 0)
(0, 0, 0, 1)
Incidence matrix
Dual: octahedral pyramid
# | TXID | Va | Vb | Ea | Eb | 3a | 4a | C1a | C2a | Type | Name |
---|---|---|---|---|---|---|---|---|---|---|---|
0 | Va | = point | ; sweep: apex | ||||||||
1 | Vb | = point | ; lateral: vertices | ||||||||
2 | Ea | 1 | 1 | = digon | ; sweep: vertices | ||||||
3 | Eb | 0 | 2 | = digon | ; lateral: edges | ||||||
4 | 3a | 1 | 2 | 2 | 1 | = triangle | ; sweep: edges | ||||
5 | 4a | 0 | 4 | 0 | 4 | = square | ; lateral: faces | ||||
6 | C1a | 1 | 4 | 4 | 4 | 4 | 1 | = square pyramid | ; sweep: faces | ||
7 | C2a | 0 | 8 | 0 | 12 | 0 | 6 | = base of pyramid: cube | ; lateral: cell | ||
8 | H4.1a | 1 | 8 | 8 | 12 | 12 | 6 | 6 | 1 | = cubic pyramid | ; |
Usage as facets
This polytope does not currently appear as facets in any higher-dimensional polytopes in the database.
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 |
18. [21]1 Cylindrone | 19. [111]1 Cubic pyramid | 20. 211 Cyltrianglinder |
List of tapertopes |