Question

Using Euler's formula find the unknown.

Faces	$?$	$5$	$20$
Vertices	$6$	$?$	$12$
Edges	$12$	$9$	$?$

Answer 1

$F+V=E+2$

$F+6=12+2$

$F=8$

$F+V=E+2$

$5+V=9+2$

$V=6$

$F+V=E+2$

$20+12=E+2$

$E=30$