Can someone me answer all the questions?

Help you answer the questions, sure!  Do the problems for you, nope.

in Problem 26 you have 2 small triangles.  In the left one you have the angle 36 degrees, which means that the other acute angle is 90-36, or 54 (degrees).  You'll need to find the height of the left triangle; finding that height is the same as determining the length of the side adjacent to the 36 degree angle.

Let that height be repr. by h.

Then tan 36 deg = h/21  Use the inverse tangent function to find the value of h.

Look at the triangle on the right.  It has a 42 deg angle, and the length of the side next to it is h (which you found above).  x is the hypotenuse.

Can you see that x*cos 42 deg = h?  Knowing h, can you now find x?

If you have any qu. about this approach, please ask questions.