Question

A pilot heading his polane due north finds the actual direction of travel to be 5.2 NE. The planes's air speed is 315 mi/h, and the wind is from die west. Find the plane's ground speed and the velocity of the wind.

Answer 1

Set up a triangle.

If the ground speed is v, then that is the northward component of the velocity. The wind speed w is the eastbound component. Add them to get the air speed. Your triangle shows that

v/315 = cos 5.2°
w/315 = sin 5.2°

Plug and chug