( 28? ) 



Nr. 



1 

 2 



3 

 4 

 5 

 6 



7 



8 



O 



10 



11 



12 



Groups 



i(3-e) 



1 



2 (e— 2) 

 e— 2 



J (5-*) 



l 



To 



(5-*) 



i , 

 T (3*-5) 



i$-e) 





 10 



7.63932 

 8.94427 

 9.44272 

 4.72136 

 6.18034 

 9.14207 

 2.91706 

 5.52786 

 8.54102 

 3.81966 



polygons represented in fig. 8 by laying down in t tie plane of the 

 diagram of* fig. 7 t lie regular pentagon projecting itself in psv and 

 the equilateral triangle projecting itself' in rr. By the remark that 

 all these polygons admit an axis of symmetry, the line /■ bisecting 

 the edge q x q % normally, and that the measures (jab, aa' of the 

 pentagon of' Nr. i> and qcde, dd' , ee' of the octogon of' Nr. 4 used 

 in lig. 8 arc taken from fig. 7 this construction will become suffi- 

 ciently clear. l ) 



We add to this the following simple general remark. The polygon 

 situated in a diagonal plane of which one of' the sides is an edge 

 of C t00 is always either a pentagon, or a hexagon, or an octagon. 

 If we once more determine the diagonal plane by means of the 

 edge normal in q to the plane of fig. 4 and the point of intersection 

 (S with />//, then the section is a pentagon if 5 lies between /> and 



') The letters (/ and c, that had to indicate points on /.", have been omitted in 

 fig. 8. 



