Answer:
choice one and choice two
Explanation:
Here is a rule: If the bisector of an angle in a triangle is perpendicular to the opposite side, the triangle is isosceles.
Since the question states that QST is isosceles, and that RT is an angle bisector, we can safely assume that RT is perpendicular to SQ.
All perpendicular line segments form right angles, so ∠QRT and ∠SRT are right angles
All right angles are equal to 90°
So, ∠QRT is 90°
All right are congruent, so ∠QRT ≅ ∠SRT
So the answer to this question is choice one and choice two