There are 44 diagonals in an 11 sided undecagon
1/2*15*(15-3) = 90 diagonals.
104 16x ((16-3)/2) =104
22-gon
A n sided figure has 1/2 n(n - 3) diagonals → a 17-gon has 1/2 x 17 x (17 - 3) = 1/2 x 17 x 14 = 119 diagonals
405 diagonals
252 diagonals
There are 119 diagonals.
It has 495 diagonals.
It has 54 diagonals
170
78
There are 44 diagonals in an 11 sided undecagon
0.5*(152-45) = 90 diagonals
A 20 sided polygon has 170 diagonals
There are 275 diagonals in a 25 sided polygon
39*36/2 = 702 diagonals.