Answer: 22°.
Step-by-step explanation: We're given the angle 158°, which is all we need. Angle u and 158°, have to add up to 180°. 180° - 158° = 22°, which is the angle measure of u. You're probably wondering how this will help us. The answer to that is it gives us the measurement of angle t, which is 158°. Now, we'll do the same thing we did with angle u, which was to make angle u add up with 158° to make 180°. We'll apply this to angle t and angle s. We already know that angle t is 158°, so angle s has to be 22° in order to add up to 180°. Therefore, your answer is 22° for angle s.
Let me know if this is right! :)