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I have problems with proving inequality :

$${a^{2}}+b^2+c^2+\frac{2}{5}abc<50$$

where $a,b,c$ are the lengths of triangle's sides, and the circumference of the triangle is $10$.

Thanks.

  • 0
    what do u mean by a circumference of a triangle.2011-05-15
  • 0
    Presumably by "circumference" what's meant is what I'd call "perimeter".2011-05-15

2 Answers 2