Jim's dog Sparky runs 50.0m northeast to a tree, then 70.0m west to a second tree, and finally 20.0m south to a third tree.Calculate Sparky's net displacement vector. I drew a picture and got an unknown triangle, which yileds the use of law of cos. I applies law of cos, to find an angle, and i get an angle to be 180 degrees. I know this value is wrong, but i know I will need at least one measure of an angle to compute the problem. I just dont see why the law of cos would go wrong here, can anybody help me out.