1. In the given figure O is the centre and PQ is the diameter of the circle. if the chord PR is produced to S and QR is joined the what will be the value of the angle QRS?

Answer:
90°
Step-by-step explanation:
since PQ is the diameter of the circle, m L PRQ = ½ × 180° = 90°.
so, as a supplementary to L PRQ, the value of angle QRS = 180 - m L PRQ = 180-90 =90°