If `A+B+C=pi`, prove that : `tan( A/2) tan (B/2) + tan (B/2 )tan (C/2)+ tan( C/2) tan (A/2) =1`

In DeltaABC , prove that: s^(2).tan(A/2)tan(B/2)tan(C/2)=Delta

In Delta ABC if tan(A/2) tan(B/2) + tan(B/2) tan(C/2) = 2/3 then a+c

If A+B+C=pi, prove that tan^2A/2+tan^2B/2+tan^2C/2geq1.

If A+B+C=pi, prove that tan^2A/2+tan^2B/2+tan^2C/2geq1.

In any Delta ABC , prove that : ((a-b)/c) = (tan (A/2) - tan (B/2))/(tan (A/2) + tan (B/2)

If A +B = 225 ^(@), prove that tan A + tan B =1- tan A tan B

In DeltaABC , prove that: (a+b+c).(tan(A/2)+tan(B/2))=2c cot(C/2)

In any DeltaABC , prove that : tan (A/2 + B) = (c+b)/(c-b) tan (A/2)

If A + B = (pi)/(4) , then prove that (1 + tan A) (1 + tan B) = 2

In triangle ABC, if |[1,1,1], [cot (A/2), cot(B/2), cot(C/2)], [tan(B/2)+tan(C/2), tan(C/2)+ tan(A/2), tan(A/2)+ tan(B/2)]| then the triangle must be (A) Equilateral (B) Isoceless (C) Right Angle (D) none of these