pentagon / triangle problem

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Re: pentagon / triangle problem

by Vemuri » Sun Apr 12, 2009 10:24 pm
tj123 wrote:attached.
what is the fastest way to solve this?
We have 6 points & we need 3 points to form a triangle. So, we can form 6c3 triangles. 6c3 => 6!/(3!*3!) = 20

Hope this helps.