There are: 0.5*(15^2 -3*15) = 90 diagonals in a 15-agon polygon
1/2*15*(15-3) = 90 diagonals.
0.5*(152-45) = 90 diagonals
There are: 0.5*(15^2 -3*15) = 90 diagonals in a 15-agon polygon
It has 495 diagonals.
There are 119 diagonals.
It has 54 diagonals
252 diagonals
fourteen. If you draw if diagonals from one vertex there are 14. fourteen. If you draw if diagonals from one vertex there are 14.
170
78
There are 275 diagonals in a 25 sided polygon
A 20 sided polygon has 170 diagonals