Acronym starodip Name pentagram - octagon duoprism Circumradius sqrt[(15+5 sqrt(2)-sqrt(5))/10] = 1.408368 Dihedral angles at {5/2} between stip and stip:   135° at {4} between op and stip:   90° at {8} between op and op:   36° Confer n/d,m/b-dip Externallinks

Incidence matrix according to Dynkin symbol

```x5/2o x8o

.   . . . | 40 |  2  2 | 1  4 1 | 2 2
----------+----+-------+--------+----
x   . . . |  2 | 40  * | 1  2 0 | 2 1
.   . x . |  2 |  * 40 | 0  2 1 | 1 2
----------+----+-------+--------+----
x5/2o . . |  5 |  5  0 | 8  * * | 2 0
x   . x . |  4 |  2  2 | * 40 * | 1 1
.   . x8o |  8 |  0  8 | *  * 5 | 0 2
----------+----+-------+--------+----
x5/2o x . ♦ 10 | 10  5 | 2  5 0 | 8 *
x   . x8o ♦ 16 |  8 16 | 0  8 2 | * 5
```

```x4x x5/2o

. . .   . | 40 |  1  1  2 | 1  2  2 1 | 2 1 1
----------+----+----------+-----------+------
x . .   . |  2 | 20  *  * | 1  2  0 0 | 2 1 0
. x .   . |  2 |  * 20  * | 1  0  2 0 | 2 0 1
. . x   . |  2 |  *  * 40 | 0  1  1 1 | 1 1 1
----------+----+----------+-----------+------
x4x .   . |  8 |  4  4  0 | 5  *  * * | 2 0 0
x . x   . |  4 |  2  0  2 | * 20  * * | 1 1 0
. x x   . |  4 |  0  2  2 | *  * 20 * | 1 0 1
. . x5/2o |  5 |  0  0  5 | *  *  * 8 | 0 1 1
----------+----+----------+-----------+------
x4x x   . ♦ 16 |  8  8  8 | 2  4  4 0 | 5 * *
x . x5/2o ♦ 10 |  5  0 10 | 0  5  0 2 | * 4 *
. x x5/2o ♦ 10 |  0  5 10 | 0  0  5 2 | * * 4
```