With usual notations in `/_\ ABC` , if `A=pi/2` and `(a+b+c)k=/_\,` then `(b+c-a)=`

With usual notations in a triangle A B C , if r_1=2r_2=2r_3 then 4a=3b (b) 3a=2b 4b=3a (d) 2a=3b

With usual notatons , in triangle ABC , prove that a(bcosC-c cos B)=b^2-c^2 .

If in a !ABC , a =2b ,and abs(A-B)=(pi)/3 then C =

With usual notatins, if in a Delta ABC,(b+c)/(11)=(c+a)/(12) =(a+b)/(13), then prove that (cos A)/(7) =(cos B)/(19) =(cos C)/(25).

With usual notations, if in a triangle ABC (b+c)/(11) = (c+a)/(12) = (a+b)/(13) , then cos A : cos B : cos C is :

With usual notations, in triangle ABC, a cos (B - C) + b cos (C - A) + c cos (A - B) is equal to

With usual notations,if in a triangle ABC(b+c)/(11)=(c+a)/(12)=(a+b)/(13), then prove that: (cos A)/(7)=(cos B)/(19)=(cos C)/(25)

With usual notation,if in a triangle ABC ,(s-a)/(5)=(s-b)/(6)=(s-c)/(7), then value of cos C is-