Answer:
Step-by-step explanation:
First you have to calculate CB in order to use sin law to calculate ∠A
CB=
CB=12.8(correct to nearest tenth)
After that, use sin law to calculate ∠A,
or 
sinA=0.695...
A=44.079...
=44.1(corrext to the nearest tenth)
Is that clear enough for you?
Answer:

Step-by-step explanation:
If AB is tangent to the circle, then angle ABO is right angle and triangle AOB is special
triangle. In this triangle, the leg that is opposite to the angle of 30° is half of the hypotenuse. Thus,

By the Pythagorean theorem,

Answer:
C. 5 units
Step-by-step explanation:
look at the graph to the left
this seems too easy so I'm probably wrong but thats how I read the question