Using the cosine rule (a^2 = b^2 + c^2 - 2bc cos A), we can work out the displacement:
Displacement = a
b = 30
c = 50
A = 180 - 35 = 145 degrees.
a^2= 900 + 2500 -1500*-0.81915...
= 3400 + 1228.728...
= 4628.72...
a = 68.034...
= 68.0m (to 3s.f.).
To work out the angle from starting place, use another configuration of the cosine rule:
[tex]cos(C)= \frac{a^{2} +b^{2}- c^{2} }{2ab} [/tex]:
cos (C)= [tex] \frac{4628.72...+900-2500}{2*68*30} [/tex]
= 3028.7.../4080
= 0.7423...
C = 42.069... degrees
= 042 bearing
