(1)^(gamma)times1^(1cot A+b cot B+c cot C=2(R+r))

a cot A+b cot B+c cot C=

If alpha, beta and gamma are the lengths of altitudes ABC and Delta be its area prove that : (1)/(alpha^(2))+(1)/(beta^(2)) + (1)/(gamma^(2)) = ((cot A + cot B + cot C))/(Delta)

a^(2)cot A+b^(2)cot B+c^(2)cot C=

a^(2) cot A+ b^(2) cot B+ c ^(2) cot C =

In Delta ABC Prove that a cot A + b cot B + c cot C = 2 ( R + r)

show that in a triangle /_ABC:a cot A+b cot B+c cot C=2(R+r)

a^(2) cot A + b^(2) cot B + c^(2) cot C "" ( abc)/( R)

In a DeltaABC, prove that: 2r le (a cot A+ b cot B+ c cot C)/(3)leR