Question

Can a 10 sided polygon have exactly 21 diagonals? Use the formula n(n-
3)/2 *

Answer 1

No

Explanation:

for a n-agon the formula is

`(n(n-3))/(2)`

so in our case n=10

`((10)(10-3))/(2) \\\\=(10*7)/(2) \\\\=5*7\\\\=35`

so no, a 10 side polygon has exactly 35 diagonals