trig
posted by Caroline on .
An airplane pilot wishes to maintain a true course in the direction 250° with a ground speed of 400 mi/hr when the wind is blowing directly north at 60 mi/hr. Approximate the required airspeed and compass heading

I have a triangle with sides 60 and 400 and the contained angle is 70°
let the resultant be R
R^2= 60^2 + 400^2  2(60)(400) cos70°
= 147183.0331
R = 383.64 mi/h
finding the angle opposite the 70°
sinØ/60 = sin70/R
sinØ = .14696..
Ø = 8.45°
so the compass heading is 250 + 8.45 = 258.5°