Hey there!
2. Your answer is A. Given a right triangle and you know one side and one angle.
It is important that these trig functions we're talking about are used for right triangles only. They don't work on other triangles. You also need at least one side and at least one angle to be able to do any of them.
3. Your answer is D. opposite/adjacent.
Tangent is the side opposite the angle over/divided by the side adjacent to the angle. There's a way to remember this, which is question 5...
5. Your answer is D. SOH-CAH-TOA.
A lot of my teachers in the past have given me this awful joke to help remember this. I'm sorry to put you through the bad joke but it does help to remember.
What did the teacher do when he stubbed his toe?
He soh-cah-toa (soaked the toe).
Sorry again.
S stands for sine, C stands for cosine, T stands for tangent, O stands for opposite (side), A stands for adjacent (side), and H stands for hypotenuse.
Hope this helps!