If a,b,c are vectors such that `a*b=0 and a+b=c`

Ifa,b,c are vectors such that a + b + c = 0 and | a | = 7, | b | = 5,| c | = 3, then the angle between c and b is a) pi//3 b) pi//6 c) pi//4 d) pi

If a,b,c are unit vectors such that a + b + c = 0 then a.b + b.c + c + c . A=

If a,b,c are three vectors such that a + b + c = 0, |a| = 1, |b| = 2, |c| = 3 then a.b+ b.c + c.a =

If a,b,c are unit vectors such that a+b+c=0 , then find the value of a.b+b.c+c.a .

If a, b, c are unit vectors such that a-b+c=0 then c*a is equal to

If a, b and c are vectors such that a .b=a .c, axx b=a xx c, a ne 0 , then show that b=c

Suppose a, b, c are three vectors such that a+b+c=0, abs(a)=abs(b)=1" and "a*b+b*c-c*a=-3//2," then "abs(c)= ________