Problema Solution

Nine unique diagonals are drawn in a regular polygon. How many sides does it have?

Answer provided by our tutors

The number of diagonals of an n-sided polygon is:

n(n − 3) / 2

Since we know that the number of diagonals is 9 we have:

n(n − 3) / 2 = 9

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click here to see the equation solved for n

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n = 6

The regular polygon has 6 sides, it is a hexagon.