Want to find angle between two vectors

1. Sep 20, 2008

amandeepmail

1. The problem statement, all variables and given/known data

Two vectors A ⃗ and B ⃗ are such that A ⃗+B ⃗=C ⃗ and A2+B2=C2 .You need to find the angle θ between the positive directions of A ⃗ and B ⃗.

2. Sep 20, 2008

CompuChip

Hint: consider
$$(\vec A + \vec B)^2 = (\vec A + \vec B) \cdot (\vec A + \vec B)$$