Question

find the number of edges in polyhedron with 10 faces and 12 vertices

Answer 1

There's a given formula ( 'Euler's rule' to be precise) stating that:
Vertices + Faces= 2+ Edges

Therefore:
12+ 10= 2 + Edges
20= No. of edges

That's it, hope that helped.

Answer 2

Heya user,

Euler's formula for a polyhedron may help :->

It says, F = no. of faces, V= no. of vertices and E = no. of edges,
Then,
---> F + V = E + 2

Substituting the values, 10 + 12 = E + 2
=> E = 10 + ( 12 - 2 )
=> E = 10 + 10 = 20;

.'. No. of edges of the polyhedron = 20