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It is: 0.5*(n2-3n) = diagonals whereas n is the number of sides of the polygon

Q: What is the formula to determine the number of diagonals in a polygon?

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By using the polygon diagonal formula or the quadratic equation formula in which in both formulae they work out that the polygon in question has 21 sides.

Using the formula (x)(x-3)/2 = Diagonals ; simply replace the diagonals with the number of diagonals you're given. Then, you'll havev (x)(x-3)/2 = Diagonals. Simplify it, and you'll be given x(power of 2) - 3X = (2)(Diagonals). Subtract the amount of diagonals from both sides, and you'll have x(power of 2) - 3X - 2Diagonals = 0. From there, use the quadratic formula to find the number of sides the polygon has.

Using the formula 0.5(n^2 -3n) whereas n is number of sides, altogether there are 104 diagonals in a 16 sided polygon

number of diagonals = n(n-3)/2 n - number of sides of the polygon

Number of diagonals in a polygon with n sides is n*(n-3)/2 A pentadecagon has 15 sides, so n = 15 Number of diags = 15*12/2 = 90

Related questions

The formula is: 0.5*(n2-3n) = diagonals whereas n is the number of sides of the polygon

It is: 0.5*(n2-3n) = diagonals whereas 'n' is the number of sides of the polygon

You can find the number of diagonals in a polygon using the formula n(n-3)/2, where n is the number of sides. Therefore an 11 sided polygon has 44 diagonals.

The formula is: 0.5*(n2-3n) where n is the number of sides of the polygon

The formula for the number of diagonals is: 0.5*(n^2-3n) whereas 'n' is the number of sides of the polygon

The formula is: 0.5*(n2-3n) = number of diagonals when n is the number of sides of the polygon

0.5*(n2-3n) where n is equal to the number of sides of the polygon

Use the formula of: 0.5*(n2-3n) whereby n is the number of sides of the polygon

Total diagonals formula: 0.5*(n^2 -3n) whereas n is the number of sides of the polygon

For a 9 sided polygon it is: 0.5*(92-(3*9)) = 27 diagonals

n side polygon has n(n-3)/2 diagonals therefore a hexagon has 9 diagonals

1/2*(n2-3n) where n is the number of sides of the polygon.