Verify Euler’s formula for these solids.

(i)


(ii)

(i) Number of faces = F = 7

Number of vertices = V = 10


Number of edges = E = 15


We have,


F + V - E = 7 + 10 - 15


= 17 - 15


= 2


Hence, Euler's formula is verified


(ii) Number of faces = F = 9


Number of vertices = V = 9


Number of edges = E = 16


F + V - E = 9 + 9 - 16


= 18 - 16


= 2


Hence, Euler's formula is verified


7