Question

A girl walks 800m on a bearing of 129°
calculate how far east and west she is from her starting piont.

Answer 1

800 cos39°
you decide whether that's east or west. It won't be both...

Answer 2

All angles are measured CW from +y-axis.
D = 800m[129o].
D = 800*sin129+(800*cos129)i = 622 - 503i.
622 meters East and 503 meters South.

Answer 3

65.2cm