Acronym  stiscu 
Name 
pentagrammic cuploid, star semicupola 
© © embedding of stiscu within sidtid  
Circumradius  sqrt(3)/2 = 0.866025 
Vertex figures  [3,4,5/2,4], [3,4,3/2,4/3]/0 
Confer 

External links 
Stiscu is an edgefaceting of sidtid, in fact it uses triangles and pentagrams of it and squares of rhom, the inscribed compound of 5 cube.
As a cuploid it has a pseudo bottom face. That one is the withdrawn {10/2} of the corresponding cupola. By that withdrawel the top base becomes a membran, as the central part becomes accessible from the outside at both sides.
As abstract polytope stiscu is isomorphic to rapescu, thereby replacing the (prograde) pentagram by a retrograde pentagon, while pseudo pentagon would become a pseudo pentagram.
Incidence matrix according to Dynkin symbol
reduced(xx5/2ox&#x by x5/2x) → height = sqrt((5+sqrt(5))/10) = 0.850651
({5/2}  pseudo {10/2})
o.5/2o.  5 *  2 2 0  1 2 1
.o5/2.o  * 5  0 2 2  0 2 2
+++
x. ..  2 0  5 * *  1 1 0
oo5/2oo&#x  1 1  * 10 *  0 1 1
.x .. & .. .x  0 2  * * 5  0 1 1 (those edges get identified)
+++
x.5/2o.  5 0  5 0 0  1 * *
xx ..&#x  2 2  1 2 1  * 5 *
.. ox&#x  1 2  0 2 1  * * 5
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