# Hi! I have a doubt on heptagons,octagon, nonagon& decagon. How many diagonals do they have? How to draw them?

Answer :

We can use formula to find number of distinct diagonals .

Number of diagonals of n - sided polygon = $\frac{n\left(n-3\right)}{2}$

So,

Number of diagonals of heptagon ( We know in heptagon we have 7 sides , So n = 7 ) = $\frac{7\left(7-3\right)}{2}=\frac{7\times 4}{2}=7\times 2$ = ** 14 **

And

Number of diagonals of octagon ( We know in octagon we have 8 sides , So n = 8 ) = $\frac{8\left(8-3\right)}{2}=\frac{8\times 5}{2}=4\times 5$ = ** 20 **

And

Number of diagonals of nonagon ( We know in nonagon we have 9 sides , So n = 9 ) = $\frac{9\left(9-3\right)}{2}=\frac{9\times 6}{2}=9\times 3$ = ** 27 **

And

Number of diagonals of decagon ( We know in decagon we have 10 sides , So n = 10 ) = $\frac{10\left(10-3\right)}{2}=\frac{10\times 7}{2}=5\times 7$ =** 35 **

And

We can draw these diagonals by joining each non consecutive vertices.

Here we have draw diagonals of heptagon , As :

You can try to draw diagonals for different polygon by yourself and if still have any doubt , Kindly get back to us so we can help you precisely .

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