The side marked 22 is a leg of the right triangle. The side marked x is also a leg of the right triangle. The angle marked 58° is right next to the side marked x. It is ADJACENT to the angle. The 22 side is OPPOSITE from the angle. The trig ratio that puts together the ADJACENT side and the OPPOSITE side is the tangent.
tan Angle= OPP/ADJ
tan 58° = 22/x
Times both sides by x
xtan58° = 22
Divide by tan58°
x = 22/tan58°
at this point you need need a calculator. There will be a button "tan" enter tan 58° and hit enter. Make sure your calculator is in degree mode. There will probably be a "deg" on the screen or in the info if you hit a "mode" button (its like settings)