The formula for the number of diagonals that an N-sided polygon has is
# diagonals = N(N-3)/2
N(N-3)/2
9(N-3)/2
9*(9-3)/2
9*6/2 = 54/2
27
Chat with our AI personalities
None.
None. Since the number of sides is odd, there can be no parallel sides.
Infinitely many. Every regular polygon with 2n sides has n pairs of parallel sides. Then there are irregular polygons which can have parallel sides. And there are also irregular shapes which have parallel sides.
Their are 4 pairs of parallel sides on an octagon. In fact, for any regular polygon with an even number of sides, there will be # of sides / 2 number of pairs of parallel lines.
There are infinitely many such shapes. A polygon with 4 or more sides can have two sides that are parallel and they need not be the same length.