The first equation is equal to the one in the question.
Hey there!
ANSWER: 
<h2>
EXPLANATION:</h2>
5% of what is 90?
If you want to find 5% of what is 90, you can try doing 90/5%.
%
To get the decimal form, you can do 90*5%.
%
Hope this helps!

Answer:
Case I, Case II
Step-by-step explanation:
For cases III and IV, you need the Law of Cosines.
The Law of Sines can be used when you have at least one side and the angle opposite. If you know two angles of a triangle, you know all three, so the given angles don't necessarily have to be opposite the given side if two angles are known.
The Laws of Sines can be applied to solve Case I and Case II.