An airplane leaves an airport and flies due west 180 miles and then 160 miles in the direction S79.17˚W. How far is the plane from the airport at this time (to the nearest mile)?

Respuesta :

Using the cosine rule  

x^2 = 180^2 + 160^2 - 2.160.180 cos 169.17

=   114574.09

x  = sqrt 114574.09 =  338 miles to nearest mile