Question

Using Euler' s formula find the unknown.
5
20
Faces
6
12
Vertices
12
9
Edges by the method F +V=E+2​

Answer 1

Answer:

By Euler's formula. (i) Faces-?,vertices-6,edges-12

Euler's formula: F+V–E=2

F+6–12=2

F=2+12–6=8

F=8

(ii) Faces-5,vertices-?,edges-9

Euler's formula: F+V–E=2

5+V–9=2

V=2+9–5=6

V= 6

(iii) Faces-20,vertices-12,edges-?

Euler's formula: F+v–E=2

20+12–E=2 ,

E=20+12–2

E=30