I need help setting these up.

1.) Use the parallelogram rule to find the magnitude of the resultant force for the two forces shown in the figure. round to one decimal place. Theta= 35 degree, b=98 lbs, c=55lb

2.) Find the magnitude and direction angle for each vector. Five the measure of the direction angle as an angle in [0,360].<6,6>

3.) Find the angle between the given vectors to the nearest tenth of a degree. a=9i + 8j, b=-8i + 7j

2 answers

1. can't see your diagram but will assume that the angle of 35° is between the two given sides, so ...
R^2 = 98^2 + 55^2 - 2(55)(98)cos 145°

2. "each" vector ? , what vector

3. a = <9,8> b = <-8,7)

a dot b = |a| |b| cosØ
-72 + 56 = √145 √113 cosØ
cosØ = -.124996..

Ø = appr 97.1805..
or 97.2° to the nearest tenth of a degree
Thank you!