JAMB - Mathematics (2006 - No. 30)

In the diagram above, POQ is a diameter of the circle PQRS. If ∠PSR = 145°, find x°

55^o

45^o

35^o

25^o

∠PSQ = 90° (∠ in semi circle)
∠PSQ + ∠QSR = 145°
90 + ∠QSR = 145
∠QSR = 145 - 90
∠QSR = 55°
BUt x° = ∠QSR (∠s in the same segment)
∴x° = 55°