Acronym	tridpy, J12
Name	trigonal dipyramid
	© ©
Vertex figure	[33], [34]
General of army	(is itself convex)
Colonel of regiment	(is itself locally convex)
Confer	uniform relative: tet   related Johnson solids: etidpy   general polytopal classes: deltahedra
External links

Incidence matrix according to Dynkin symbol

oxo3ooo&#xt   → both heights = sqrt(2/3) = 0.816497
(pt || pseudo {3} || pt)

o..3o..    | 1 * * | 3 0 0 | 3 0
.o.3.o.    | * 3 * | 1 2 1 | 2 2
..o3..o    | * * 1 | 0 0 3 | 0 3
-----------+-------+-------+---
oo.3oo.&#x | 1 1 0 | 3 * * | 2 0
.x.3...    | 0 2 0 | * 3 * | 1 1
.oo3.oo&#x | 0 1 1 | * * 3 | 0 2
-----------+-------+-------+----
ox.3...&#x | 1 2 0 | 2 1 0 | 3 *
.xo3...&#x | 0 2 1 | 0 1 2 | * 3

or
o..3o..     & | 2 * | 3 0 | 3
.o.3.o.       | * 3 | 2 2 | 4
--------------+-----+-----+--
oo.3oo.&#x  & | 1 1 | 6 * | 2
.x.3...       | 0 2 | * 3 | 2
--------------+-----+-----+--
ox.3...&#x  & | 1 2 | 2 1 | 6