You need to go back and look over your shortcuts for sine, cosine, and tangent. Also make sure you label which angle is theta.
For number 20, they give you csc theta = 5/3 and since csc = 1/sin you can flip the answer to get sin=3/5. This means that the opposite length is 3 and the hypotenuse is 5 (your drawing is wrong). Use Pythagorean Theorem to find the other side, which would be
This gives a value of 4 for x, so now you have a triangle who's hypotenuse is 5 with sides equal to 3 and 4.
Use this to find your trig functions, and to help with 22.
leave a comment if you need more help.