The Statement:
AB is a Diameter is wrong because a Diameter is a straight line passing from side to side through the center. In this case it is a Chord because it is a straight line segment whose endpoints both lie on the circle.
ST,SP and Sq are radius this is true becuase they are all lines that start from any point of the circumference and end at the center of the circle
SQ= 12 cm this is false because SQ is a radius and SQ=ST, ST=6cm
PQ=12 cm this is true because PQ is a diameter
