33°
Since it's a right triangle that has an immediate 90° angle, we have 90°'s left to worry about. We have two angles to worry about it, and since one angle is bigger than the other by 24°, it means that the gap between them is 24°. After doing some mental math, you get 57° + 33°. The gap between them is 24°, and they add up to 90°. Finally, since you're looking for the smaller angle in this problem, then 33° would be your answer.