Answer:
So If you start with sinØ = .5
your calculator is programmed to always give the closest angle to 0, and that would be 30°
You probably used the cosine law to find the first angle. A suggestion is to always find the largest angle first. If that happens to be an obtuse angle, your calculator will find the correct angle.
Of course there can only be one obtuse angle in a triangle, so using the sine law for your second angle does not result in any problems
notice that in your solution 78 and 102 add up to 180 , and sin 78 = sin(180-78) = sin 102
I would have found angle S first, the largest angle always opposite the largest side.
7^2 = 5^2 + 4^2 - 2(5)(4)cosØ
40cosØ = -8
cosØ = -8/40 = -1/5
Ø = 101.537°
Now you can use the sine law and you will find the correct other angles.
Step-by-step explanation:
