# Math

The number of diagonals D I a polygon of n sides is given in the formula D=n(n-3)/2.
Use the formula to find:
A. The number of diagonals in a polygon with 9 sides.

B. The number of sides of a polygon with 90 diafonals.

1. 👍 0
2. 👎 0
3. 👁 90
1. just plug in the numbers. Should not be too hard.

1. 👍 0
2. 👎 0
posted by Steve

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