## anonymous one year ago Help with Laws of Sines!!! Will Medal!

1. anonymous

2. welshfella

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3. welshfella

sine rule is a / sin A = b / sin b = c / sin C

4. welshfella

thats 200 not 20 ( in the diagram)

5. anonymous

So we would set the equation up like:$\sin(B) = \frac{ 200 }{ \sin(52) } \times 234?$

6. welshfella

to find angle B we have 234 / sin B = 200/ sin 52

7. welshfella

cross multiply 200 sin B = 234*sin 52 sin B = (234* sin52) / 200

8. anonymous

sin B = .9219

9. welshfella

0.9220 to 4 dec places

10. anonymous

Ok! So now how would we find the angles for B?

11. welshfella

use your calculator - the key marked sin-1

12. anonymous

Oh I completely forgot about arcsin! Thanks for reminding me. Anyway, I got 67.22 degrees! Are there going to be more than one answer or is this it?

13. welshfella

hmmm i'll have to check if theres another answer 76.22 is correct

14. anonymous

Great! I am not sure if there is another answer but if there is, it should be 112.8

15. welshfella

yes hm i've forgotten this bit of trig - i dont think there is as the length of b would have to be grater than 235

16. anonymous

Ok, so would you say there is only one answer to this problem making it B?

17. welshfella

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18. welshfella

yes

19. anonymous

It was A :( but that;s okay :) Thank you for your help!

20. welshfella

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21. welshfella

yes that's right - theres the 2 possibilities in the diagram

22. anonymous

Oh I see now! Thank you!

23. welshfella

its call ed the ambiguous case where 2 angles are possible

24. anonymous

I don't like these cases hahaha. Always trick me!