Sides: 8
Diagonals : 20
An octagon has 8 sides and 20 diagonals so the question doesn't make sense
0.5*(64-24) = 20 diagonals
An octagon has 16 diagonals.
There are 20 diagonals
8 diagonals
4 diagonals
20 diagonals For any n-sides polygon, the formula for the number of diagonals is (n/2) x (n-3), so for an octagon it is (8/2) x (8-3) = 4 x 5 = 20.
None, if it is an irregular octagon.
A polygon with n sides has n*(n-3)/2 diagonals (not diagnols!).So, an octagon has 8*5/2 = 20 of them.
20
20
An octagon has four (4) diagonals, each connecting two opposite vertices.