For this case what you should do is use the following trigonometric relationship:
sin (x) = C.O / h
Where
x: angle
C.O: opposite leg
h: hypotenuse
Substituting the values we have:
sen (60) = long / h
sen (60) = 3 / h
h = 3 / sin (60)
h = 3.46
Answer:
h = 3.46
Answer: -9.1
Explanation
-3x +12.4=39.7
First minus 12.4 from both sides
-3x +12.4=39.7
-12.4 -12.4
-3x=27.3
Now devid both sides by -3
X= -9.1
the answer is the third option, starting with degree 11.
