Acronym ditra Name ditriangular trapezoprism ` ©` Circumradius sqrt[(a+b)2+c2]/2 Coordinates (a/2, (a+2b)/sqrt(12), sqrt[c2-(b-a)2/3]/2)       & all changes of sign in first coord, resp. even changes of sign in other coords (b/2, (2a+b)/sqrt(12), -sqrt[c2-(b-a)2/3]/2)      & all changes of sign in first coord, resp. even changes of sign in other coords ((a+b)/2, (b-a)/sqrt(12), -sqrt[c2-(b-a)2/3]/2)   & all changes of sign in first coord, resp. even changes of sign in other coords Confer uniform variant: hip Externallinks

The variant with (a,b,c) = (x,x+h,q) occurs as the mere base-edge alternated faceting s2s6x obtained from the twip.

Incidence matrix according to Dynkin symbol

```ab3ba&#c   → height = sqrt[c2-(b-a)2/3]
a < b
c > (b-a)/sqrt(3)

o.3o.    | 6 * | 1 1 1 0 0 | 1 1 1 0
.o3.o    | * 6 | 0 0 1 1 1 | 0 1 1 1
---------+-----+-----------+--------
a. ..    | 2 0 | 3 * * * * | 1 1 0 0
.. b.    | 2 0 | * 3 * * * | 1 0 1 0
oo3oo&#c | 1 1 | * * 6 * * | 0 1 1 0
.b ..    | 0 2 | * * * 3 * | 0 1 0 1
.. .a    | 0 2 | * * * * 3 | 0 0 1 1
---------+-----+-----------+--------
a.3b.    | 6 0 | 3 3 0 0 0 | 1 * * *  ditriangle
ab ..&#c | 2 2 | 1 0 2 1 0 | * 3 * *  trapezium
.. ba&#c | 2 2 | 0 1 2 0 1 | * * 3 *  trapezium
.b3.a    | 0 6 | 0 0 0 3 3 | * * * 1  ditriangle
```
```or
o.3o.    & | 12 | 1 1 1 | 1 2
-----------+----+-------+----
a. ..    & |  2 | 6 * * | 1 1
.. b.    & |  2 | * 6 * | 1 1
oo3oo&#c   |  2 | * * 6 | 0 2
-----------+----+-------+----
a.3b.    & |  6 | 3 3 0 | 2 *  ditriangle
ab ..&#c   |  6 | 1 1 2 | * 6  trapezium
```