To prove that sum of two sides of a triangle minus the third side is less than the third side?
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let the sides be $\displaystyle a,b,c$ so you have to prove $\displaystyle a+b-c<c$ Keep in mind $\displaystyle a+b>c$
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Last edited by soni; Jul 14th 2010 at 09:24 PM.
Originally Posted by soni but how i can prove that a + b > c ? That is a given otherwise you would not have a triangle.
will you give me proof of this question i.e. a + b - c < c ?
Let's re-write it like this $\displaystyle a + b - c < c$ $\displaystyle c> a + b - c$ and because $\displaystyle a+b>c$ then it still holds that $\displaystyle a+b> a + b - c$ now given $\displaystyle a,b, c>0$ then we must be finished!
Thanks a lot
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