# Homework Help: Paralellogram diagonals

1. Sep 12, 2010

### Larrytsai

1. The problem statement, all variables and given/known data
Find the length of the two diagonals of a paralellogram with the sides (-2,-2) and (-10,-2)

2. Relevant equations

3. The attempt at a solution
What I have tried is, I drew out the 2 vectors, and then drew out their components and used trig to find the angles where the connect. I also found the magnitude of both the vectors.
Am i on the right track?

2. Sep 12, 2010

### Staff: Mentor

Not really. If u = <-2, -2> and v = <-2, -10> are your two vectors, a vector that represents the main diagonal of the parallelogram is u + v. The other diagonal is given by u - v.

3. Sep 12, 2010

### Larrytsai

OMG I totally missed that oh man I fail! Thanks so much, I over complicated it!!!!