In any `DeltaABC`, prove that : `a^2 +b^2 +c^2 = 2 (bc cos A + ca cos B + ab cos C)`.

In Delta ABC, prove that a^(2)+b^(2)+c^(2)=2(bc cos A+ca cos B+ab cos C)

In Delta ABC prove that a^(2)+b^(2)+c^(2)=2(bc cos A+ca cos B+ab cos C)

In any ABC,2(bc cos A+ca cos B+ab cos C)=

In any DeltaABC , 2 (bc cos A + ca cos B + ab cos C) =

In any Delta ABC, prove that :a cos A+b cos B+c cos C=2a sin B sin C

Prove in any triangle ABC that (i) a^(2)+b^(2)+c^(2)=2(bc cos A +ca cos B+ ab cos C) (ii) (b+c) cos A+(c+a)cos B+(a+b) cos C = a+b+c .

In any DelataABC prove that "a(cos C - cos B)=2(b-c)cos"^(2)A/2

In any Delta ABC, prove that : (cos A)/(b cos C+c cos B)+(cos B)/(c cos A+a cos C)+(cos C)/(c cos B+b cos A)=(a^(2)+b^(2)+c^(2))/(2abc)

In any Delta ABC, prove that :a(b cos C-c cos B)=b^(2)-c^(2)

In any Delta ABC, prove that: (cos A)/(b cos C+c cos B)+(cos B)/(c cos A+a cos C)+(cos C)/(a cos B+b cos A)=(a^(2)+b^(2)+c^(2))/(2abc)