How many diagonals can be drawn from a vertex of an n-gon?

A.) n - 3

B.) n - 2

C.) n - 1

D.) n

Question

How many diagonals can be drawn from a vertex of an n-gon?

A.) n - 3

B.) n - 2

C.) n - 1

D.) n

perl · Answer

I would start by doing examples and then looking for a pattern.

anonymous · Answer

I got A. Is that right?

abdullahm · Answer

wrong.

abdullahm · Answer

Lets take a pentagon and see how many triangles it has.

abdullahm · Answer

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anonymous · Answer

5

perl · Answer

A rectangle has n=4 sides. How many diagonals can you draw.
A pengtagon has n=5 sides. How many diagonals can you draw.

abdullahm · Answer

also, if you remember the formula for finding out the sum of the interior angles of a polygon with n sides, that is a good hint for you :)

anonymous · Answer

I still don't understand..

abdullahm · Answer

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I cut it once, and now we got one triangle. Can you make another without ruining the first triangle?

anonymous · Answer

yes

abdullahm · Answer

Can you draw that line, please. Use the button in the drawing that says "Copy Previous Drawing"