Question 890975: Solve Δ ABC with A = 70°, b = 30, and c = 51
Answer by nerdychic16(11)   (Show Source):
You can put this solution on YOUR website! The illustration may seem confusing so I am going to walk you through it.
First of all, it helps tremendously to make a triangle and label it with the information given. As you can see, I've done that at the top.
Next, it is apparent that you have to use the law of signs and law cosines in order to solve this triangle. I started off with the law of cosines in order to solve for "a". All you do is plug in all of the information that you have and solve for "a". It's pretty self-explanatory.
Now, you have to solve for the angle "B". In order to do this, you have to use the law of sines. Again, plug in what you have, and used cross multiplying to solve the equation. In order to get B by itself, you have to multiply by the inverse sine, which you must do on a graphing calculator.
Lastly, in order to find angle C, you can subtract the angles that you already have from 180. A more accurate way of finding angle C is to use the law of sines to solve for it.
Hope this helped!
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