Hi trigcalc4! Let me try the first one for you.
We know that in a right triangle is OPPOSITE/ADJACENT, so we can assume that Opposite = 3 and Adjacent is = 1 so the hypotenuse is by Pythagorean Theorem.
We also know that is equal to HYPOTENUSE/ADJACENT so
We know that
So we're done!
The others are relatively easier and you can try them by yourself.
If your still confused feel free to ask again.