Please, i need help for my homework. Thank you.

Question

Jan and Dean started hiking from the same location at the same time. Jan hiked at 5 mph with a bearing of N12°E, and Dean hiked 4 mph with a bearing of N31°W. Howa far apart were they after 5 hours? Answer: ____miles

Answer 1

construct triangle

with sides = 5 hours times speed = 5x5 and 5x4 =

25 and 20

angle between the 2 sides = 12+31=43 degrees = angle D

use cosine law

d^2 = a^2 + b^2 -2abCosD

d^2= 20^2+25^2-2(20)(25)cos43

d= sqr(1025 -500cos43)

= about 25.68 miles apart after 5 hours