The formula for the number of diagonals (that is, lines joining non-adjacent vertices) belonging to any shape is n(n-3)/2. Therefore, an eighteen-sided polygon has 18 x (18 - 3)/2 = 135 diagonals.
An octadecagon, also called an octakaidecagon, has 18 sides, from the Greek octa-, signifying 8, the connector -kai-, and deca- signifying 10.
It has 2 Diagonals!!!
2 diagonals
It has 27 diagonals
14 diagonals
A regular octadecagon (an eighteen sided polygon) would have nine diagonals.
An octadecagon is an 18 sided polygon.
It has 18
An octadecagon, also called an octakaidecagon, has 18 sides, from the Greek octa-, signifying 8, the connector -kai-, and deca- signifying 10.
It has 1,345,890 diagonals
24 diagonals
2 diagonals
It has 2 Diagonals!!!
There are 20 diagonals
It has 27 diagonals
It has 2 diagonals
20 diagonals