1. The problem statement, all variables and given/known data a person goes 180 m due west then 210 m 45 degrees east of south then 280 m 30 degrees east of north. After a fourth displacement the person is back where they started. what is the fourth vector? 3. The attempt at a solution So I first added the first two vectors of 180 and 210 using the cosine rule giving me 223 meters then added that sum with the third to get the fourth again using the cosine rule this gave me 272 m. However, the answer in my book says it should be 144m, what did I do wrong? Thanks for the help!