(i) V + F = E + 2

6 + F = 12 + 2

F = 14 - 6

F = 8

Therefore number of faces are 8

(ii) V + F = E + 2

V + 5 = 9 + 2

V = 11 - 5

V = 6

Therefore number of vertices are 6

(iii) V + F = E + 2

12 + 20 = E + 2

E = 32 - 2

E = 30

Therefore number of edges are 8