1. The problem statement, all variables and given/known data Suppose u=(-2,-10) and v=(-2,-2) are two vectors that form the sides of a parallelogram. Then the lengths of the two diagonals of the parallelogram are... 2. Relevant equations 3. The attempt at a solution I tried using pythagrean theorem and some trig to find the angles, then i thot finding the internal angle of the paralellogram i can divide it by 2 and find half of the diagonal then multiply it by 2. The angle i found was 16.85 degrees. with that i would use cos(16.85)*sqrt(104) to find half of the length of the diagonal. Am i on the right track?