ok
RT = 12
PT = 1
TQ = 12
ok
RS = 24 but RT is half the distance of RS, so RT = 12
The diameter = 26, and the line RS = 24, so the difference between both lines is 2, but as we just one to know the length of the half PT = 1.
PQ = 13 and PT = 1 so QT = PQ - PT
QT = 13 - 1 = 12