A ship is sailing due north. At a certain point the bearing of the lighthouse 12.5 km away is N 38.8 degrees E. Later on, the captain notices that the bearing of the lighthouse has become S 44 degrees E. How far did the ship travel between the two observations of the lighthouse?

1 answer

Did you make your sketch?

I have a triangle with angles 38.8° , 136°, and 5.2°
using the Sine Law:
If d is the distance travelled during the two observations ....
d/sin5.2 = 12.5/sin136
s = 12.5 sin 5.2/sin136= 1.63 km