Acronym ... Name hi dimpled in by 120 ikadoes Circumradius ... Dihedral angles at {3}type A between ike and tettype a:   360°-arccos[-sqrt(5/8)] = 217.761244° at {3}type B between tettype a and tettype b:   360°-arccos[-(1+3 sqrt(5))/8] = 195.522488° at {3}type C between tettype b and tettype b:   arccos(1/4) = 75.522488° Confer roxahi

From roxahi, a degenerate segmentoteron with zero height, it can be seen that it is truely possible to excavate a hi at all does simultanuously using ikadoes. In fact, this non-selfintersecting concave polychoron is derived such.

The above mentioned decomposition shows on the other hand, that it also can be buit up as an external blend of rox with 600 attached octpies (then supporting the vertices of hi) and 1200 pens (then supporting the edges of hi). – As the dihedral angle between the base doe and the lacing peppies of ikadoe is 72° and the dihedral angle between adjacent does of hi is 144°, it becomes clear that the peppies (formerly supporting the pentagons in that decomposition) cannot be saturated diadically here.

Incidence matrix

```720   * |   10    5    0 |   10   20    5   0 |   2   10   10  (rox kernel vertices)
* 600 |    0    6    4 |    0   12   12   6 |   0    4   12  (hi hull vertices)
--------+----------------+--------------------+--------------
2   0 | 3600    *    * |    2    2    0   0 |   1    2    1
1   1 |    * 3600    * |    0    4    2   0 |   0    2    4
0   2 |    *    * 1200 |    0    0    3   3 |   0    0    3
--------+----------------+--------------------+--------------
3   0 |    3    0    0 | 2400    *    *   * |   1    1    0  (type A)
2   1 |    1    2    0 |    * 7200    *   * |   0    1    1  (type B)
1   2 |    0    2    1 |    *    * 3600   * |   0    0    2  (type C)
--------+----------------+--------------------+--------------
12   0 |   30    0    0 |   20    0    0   0 | 120    *    *  (ike)
3   1 |    3    3    0 |    1    3    0   0 |   * 2400    *  (tet, type a)
2   2 |    1    4    1 |    0    2    2   0 |   *    * 3600  (tet, type b)
```