SOLUTION: If a regular polygon has a total of nine diagonals, how many sides does it have?

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Question 698952: If a regular polygon has a total of nine diagonals, how many sides does it have?
Answer by MathLover1(20850)   (Show Source): You can put this solution on YOUR website!

The formula for the number of diagonals in a polygon with sides is:

Now solve this for diagonals:



.....use quadratic formula








..we will need only positive solution




So the number of sides is .

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