Question Details	Asked By	Asked On
Distance of ship from its starting point	aab072588	07/05/05
thanks for your response on my previous problem. new one: Starting at point A, a ship sails 18.5 km on a bearing of 189 degrees, then turns and sails 47.8 km on a bearing of 317 degrees. find the distance of the ship from point A.
Clarification/Follow-up by aab072588 on 07/11/05 5:38 pm: thanks for your response again. i have another question thoug - how do you know that the angle between the two sides is 317 - 189? Clarification/Follow-up by Jim.McGinness on 07/12/05 9:09 am: I'm glad you're still asking questions. Clarify a few things for me, so I can try to help your further. When you read these problems, do you understand what the term "bearing" means? It's a compass direction where north is 0 degrees, south is 180 degrees, etc. When the ship is sailing on a bearing of 189 degrees, it is traveling just a little bit westerly of due south. When it turns to travel on a bearing of 317, it is going nearly north-west. The two legs of the journey make an angle whose measure is the difference in the two bearings, hence 317-189 or 128 degrees. But I was wrong to say that this is the angle of the triangle. It's the outside angle through which the ship turns. The inner angle -- which is what you'd use for the triangle, is 128-180, or 52 degrees. It's much clearer if you draw yourself a diagram -- something which answerway doesn't have good facilities for.... Is this enough for answering the most recent question about the two villages in the forest? They all involve drawing a triangle, noting which sides or angles have known (or easily solved) measures, then using trigonometry to determine the asked-for unknown side or angle.
Answered By		Answered On
Jim.McGinness		07/05/05
This time you have a triangle with one side 18.5 km, another side with 47.8 km, and an angle of (317-189) between them. Sketch out the path of the ship for yourself. The missing side of the triangle is the distance to point A. You can use trigonometry to determine the length of the third side, but it's a little tougher than the first problem because we don't know it's a right triangle.

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