We would use the sine function because we have an angle the hypotenuse, and the unknown opposite side.
sin(x)=opposite/hypotenuse
sin(60)=x/30
√3/2=x/30 (cross multiply)
30*√3/2=x (divide numerators and denominators by 2)
x=15√3 ft.
So the correct answer is A
Hope this helps
This is hard to understand , do u have a photo
You need this key result: in any polygon, the sum of the interior angles is

where
is the number of sides of the polygon.
Your polygon has seven sides, and the measures of all angles are given. So, we can write

Again, we've simply written that the sum of all interior angles is the number of sides, minus two, times 180.
We can simplify both sides: we sum like terms on the left hand side, and we easily compute the right hand side:

and we can solve this equation for
by dividing both sides by 30:

Finally, the required angles is 
Answer:
230 - 151 + 180 + (43 - 12) = 290
Step-by-step explanation:
Use PEMDAS.
Evaluate the expression in the parentheses:
230 - 151 + 180 + (43 - 12)
43 - 12 = 31
230 - 151 + 180 + 31
Add and Subtract From Left to Right:
230 - 151 + 180 + 31
79 + 180 + 31
259 + 31
290
<em>None of the given options are correct. </em>