Answer: 
=========================================================
Explanation:
Use the pythagorean trig identity
and plug in the fact that 
Isolating sine leads to
. I'm skipping the steps here, but let me know if you need to see them.
The result is negative because we're in quadrant 4, when y < 0 so it's when sine is negative.
Therefore,

Answer:
4
Step-by-step explanation:
H (height the 2x4 contact the fence)
sin 30° = H / 8
1 /2 = H / 8
H = 1/2 * 8 = 4
The answer is (2,889 mi) hope it helps and have a great day!
Answer:
12
Step-by-step explanation:
Remark
I can't use a symbol for the currency. I'll just get the answer in numbers. You can add the symbol.
Solution
First day: 50
Second day: - 20
Third day: - 18
50 - 20 - 18 = 12