1. The problem statement, all variables and given/known data A sailboat sails 2km east, then 5km at 40° west of north, then sails off in a third direction. After the third leg of the trip, the sailboat returns to its starting point by sailing 15 km at 60° west of north. How far and in what direction did the sailboat sail during the third leg of its trip? Leg 1: 2km to the right (east) 0° Leg 2: 5km up and to the left (northwest) 40° Leg 3: unknown Leg 4: 15km up and to the left (northwest) 60° Since I was told a direction, I assumed the kilometers would be the force in these equations. (This could be wrong, but I didn't know what else to try.) 2. Relevant equations I thought I could use [itex]\Sigma[/itex]F=0 F1 + F2 +F3 + F4 = 0 F3 = -F1 - F2 - F4 then I could use pythagoreans theorem and arc tangent to solve for magnitude and direction. 3. The attempt at a solution F1 + F2 +F3 + F4 = 0 F3x = -2cos0 - 5cos40 - 15cos60 F3x = -13.33 F1 + F2 +F3 + F4 = 0 F3y = -2sin0 - 5sin40 - 15sin60 F3y = 9.77 From here you would draw two arrows on a set of coordinate axis then use F3x and F3y to find F3. But the answer I come out to isn't equalling the answer in the book. I just have no idea what I'm doing wrong or how to go about this question correctly. Any help would be very much appreciated.