1. The problem statement, all variables and given/known data If a,b,c are three -zero vectors such that each one of them are perpendicular to the sum of the other two vectors, then the value of | a, b, c|2 is |a|2 + |b|2 + |c|2 |a| + |b| + |c| 2(|a|2 + |b|2 + |c|2) ½(|a|2 + |b|2 + |c|2) 2. Relevant equations a.b = ab cosθ |axb|= ab sinθ 3. The attempt at a solution First I am not understanding the notation in question of which we have to find value. It does not makes sense of having three zero vectors.