If `vec(a) , vec(b) and vec(c )` be three vectors such that `vec(a) + vec(b) + vec(c )=0` and `|vec(a)|=3, |vec(b)|=5,|vec(C )|=7`, find the angle between `vec(a)` and `vec(b)`.

Let vec(a), vec(b) and vec(c) be three vectors such that vec(a) + vec(b) + vec(c) = 0 and |vec(a)|=10, |vec(b)|=6 and |vec(c) |=14 . What is the angle between vec(a) and vec(b) ?

Vectors vec(a), vec(b) and vec(c ) are such that vec(a) + vec(b) + vec(c ) = 0 and |vec(a)| = 3, |vec(b)| = 5 and |vec(c )| = 7 . Find the angle between vec(a) and vec(b) .

If vec(a)+vec(b)+vec( c )=0 and |vec(a)|=6,|vec(b)|=5,|vec( c )|=7 then find the angle between the vectors vec(b) and vec( c ) .

If vec(a), vec(b), vec(c ) are three vectors such that vec(a) + vec(b) + vec(c ) = 0 and | vec(a) | =2, |vec(b) | =3, | vec(c ) = 5 , then the value of vec(a). vec(b) + vec(b) . vec( c ) + vec(c ).vec(a) is