For a perpendicular bisector
There are two rules.
1) It is perpendicular to the segment so it makes an angle of 90°
2) It divides the segment in two equal parts or it passes through the midpoint of the segment.
As RS is the perpendicular bisector of PQ.
So T is the midpoint
m<PTR = 90° is true
T is the midpoint of PQ is true.
RS is the perpendicular bisector of PQ is false
RS ⊥ PQ is true
RT = ST is false
PT = QT is true
A, B, D & F are true.