Finding resultant force from three forces using law of cosines

[aparra2]

using the law of cosine , compuete the magnitude of the resultant force. Compute the angle of orienttion from the relationship tan thetha
2 F1=200g at 30 degrees, F2=200g at 120 degrees, F3=200g at 150 degrees. (the value should be close to 430 g of force at 103 degrees.
this is what i get but it dosent seem right 386.40 g at -14 degrees.

 

[cristo]

Well, how have you gone about solving the problem? Draw a diagram to start, then set up equations; post your work. We can't tell you if you're right if we can't see what you've done!