m∠S = 45°; m∠T = 90°; m∠Q = 45°
Explanation
Since ST⊥TQ, this means that m∠T = 90°.
This means that m∠S+m∠Q = 180-90 = 90°.
Since ST = TQ, this means that the other two angles, formed by the legs and the hypotenuse, must be congruent. 90/2 = 45° for each angle.