State the number of faces, number of vertices and the number of edges of :

(i) a pentagonal pyramid

(ii) a hexagonal prism

Verify Euler's formula for the following three dimensional figures :

(i)

(ii)

(iii)

Can a polyhedron have :

(i) 3 triangles only ?

(ii) 4 triangles only ?

(iii) a square and four triangles?

Using Euler's formula, find the values of x, y and z