changed some of the wording:
changed which meet at an angle" to "that form at an angle"
changed both north and east to northeast
and added the hint:
Draw a 30/60/90 triangle and note that one boat is going twice as fast as the other. Since then we can use 30/60/90 triangle, otherwise it might be this triangle:
that is not a right triangle. Comparing it to 30/60/90 we can see that this gives a right triangle.
https://ximera.osu.edu/mooculus/appliedRelatedRates/exercises/exerciseList/appliedRelatedRates/exercises/relatedRatesApplied3
changed some of the wording: changed which meet at an angle" to "that form at an angle" changed both north and east to northeast and added the hint: Draw a 30/60/90 triangle and note that one boat is going twice as fast as the other. Since then we can use 30/60/90 triangle, otherwise it might be this triangle:
that is not a right triangle. Comparing it to 30/60/90 we can see that this gives a right triangle.