Question

An airplane travels at 190.0 km / h for exactly 3 hr on a bearing of 298 degrees from St. Louis. At the end of this time, how far west of St. Louis is the plane?

Answer 1

An airplane travels at $190.0\mathrm{km}/\mathrm{h}$ for exactly 3 hr on a bearing of 298 degrees from St. Louis. At the end of this time, how far west of St. Louis is the plane?

1) Find inside corner:

360-298=62(degree)

2) Calculate distance that plane flights

$190^{*}3 = 570(\mathrm{km})$

3) Calculate how far west is plane

$570 \cdot \cos(62{}^{\circ}) = 267.6(\mathrm{km})$

Answer: 267.6 km.