SOLUTION: a polygon has 90 diagonals. how many sides does it have?

Question 222148: a polygon has 90 diagonals. how many sides does it have?
Answer by solver91311(24713) (Show Source): You can put this solution on YOUR website!

There are

diagonals in a

-sided polygon. Set the formula equal to 90 and solve for

.

Hint: You will end up with a factorable quadratic. You will get two roots. Exclude the negative root because you cannot have a negative number of sides.

John

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