As one can see, the measure of angle (RST) is (90) degrees. This is indicated by the box around the angle. As a general rule, when there is a box around an angle, the angle measure if (90) degrees. It is also given that the measure of angle (RSU) is (25) degrees. As per the given diagram, the sum of the measures of angles (RSU) and (UST) is (RST). Therefore, one can form an equation and solve for the measure of angle (UST).
