0
Anonymous
a triangle has 0 diagnols
Wiki User
2
8
44
35
None
A polygon with n sides has n*(n-3)/2 diagonals (not diagnols!).So, an octagon has 8*5/2 = 20 of them.
six
3
no
It is an octagon
Formula: 0.5*(n2-3n) where n is the number of sides