Choosing a method for solving a triangle

Question

Two ships sailed from Point A at the same time. One sailed 28 nautical miles due east in 4 hours and the other sailed 36 nautical miles in the same time on a bearing of 158ºT. Find the distance between the ships.

Answer 1

You will have to use the Law of Cosines:

 

a² = b² + c²  - ( 2bc × cos A )

 

in this case, 

a = distance between the ships

b = 28

c=36

A = 158 degrees

 

so,

a = √( 28² + 36² - ( 2(28)(36) × cos 158 )

a ≈22.17