Question

how many diagonals does a 20-sided polygon have?

Answer 1

@nickiliz do you know combinations?

Answer 2

@nickiliz ?

Answer 3

no

Answer 4

^^ @ash2326

Answer 5

Hmm. There's actually a pretty formula for it:

\( \color{Black}{\Rightarrow \Large {n(n - 3) \over 3}}\)

Answer 6

Oops.
n(n - 3)/2*

Answer 7

@nickiliz put n=20 in the formula suggested by @ParthKohli and find the no. of diagonals

Answer 8

@nickiliz did you try?

Answer 9

is the answer 170?

Answer 10

@ash2326 @ParthKohli