MacMahon, Percy Alexander, 1854-1929 · Cambridge [Eng.] The University press · leaf 55
NE W MA THEM A TICAL PASTIMES 40 This is exhibited by two arrangements for the contact system Ci,i,i,i which are given m fig. 47. Cl,I,I,I Bi2,o,o,o … Ci,i,i,i B6,6,o,o Fig. 47. The first is symmetrical in colour about the axis AB. The second diners from the first both in type of boundary and in internal structure. In the first the triangles have two aspects, and in the second four aspects. In order to deal with the internal structure by type we…
Mathematical recreations
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