Answer:
not closed
included
closed
included
Step-by-step explanation:
5/20 = 1/4. All the rest of the fractions reduce to 1/5.

Geometry Rule: SOH CAH TOA.
Sine = opposite over hypotenuse
Cosine = adjacent over hypotenuse
Tangent = opposite over hypotenuse
I won't solve all of these for you because I find that solving it on your own is an important step in learning to actually understand how this works.