In `DeltaABC`, If `1/(a+b)+1/(b+c)=3/(a+b+c)`, then `angleB=?`

If in DeltaABC,1/(a+c)+1/(b+c)=3/(a+b+c) , then angleC is equal to

In DeltaABC , if 1/(a+c)+1/(b+c)=3/(a+b+c) then show that C=60^@

In DeltaABC , if (1)/(b+c)+(1)/(c+a)=(3)/(a+b+c) , then C is equal to

In DeltaABC, " if" (1)/(a+c)+(1)/(b+c)=(3)/(a+b+c) then show that C=60^(@)

In DeltaABC if (b)/(c+a)+(c)/(a+b)=1 then

In DeltaABC, if (a+b+c)(b+c-a)=3bc , then A=

In A DeltaABC , if a = 2 , b = 3 and sin A = 2/3 then angleB is (a) 90^(@) (b) 80^(@) (c) 110^(@) (d) 140^(@)

In triangleABC, if a=2, b=1, c=sqrt(3) , then angleB=