20. And the fact that it is regular is irrelevant.
5 from each vertex. So 8 vertices would (you'd think) give 8*5 = 40. Except that you would then be counting each diagonal twice - once from each end. So you need to divide by 2.
40/2 = 20.
8 diagonals
4 diagonals
It has 20 diagonals and is made up by 6 triangles
no
An octagon has 16 diagonals.
There are 20 diagonals
19 * * * * * The correct answer is 8*(8-3)/2 = 20
None, if it is an irregular octagon.
16 diagonals* * * * *5. To all vertices except itself and one each on either side.
20
20
An octagon has four (4) diagonals, each connecting two opposite vertices.