how do you determine the number of sides of a polygon?

The polygon has a total of 90 diagonals
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2 Answers

the formula for the number of diagonals of an n-side polygon is

n(n-3)/2

so n(n-3)/2=90

n(n-3) =180

n^2-3n -180=0

(n-15)(n+12)=0

n=15 sides
by Level 5 User (12.9k points)
90 yuneek diagonals impli 92 sides

But not if NE kross anuther
by

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