341To give some context: Euler's inequality. http://en.wikipedia.org/wiki/Euler%27s_inequality
in a triangle,R=2r then the triangle is
a)right angle
b)isosceles
c)equilateral
d)none
-
UP 0 DOWN 0 0 2
2 Answers
1r=4Rsin\left(\frac{A}{2} \right)sin\left( \frac{B}{2}\right)sin\left(\frac{C}{2} \right)
putting r=2R we get RHS=1/8 which can be easily seen to be true for A=B=C=60 so option c is correct
341