WAEC - Mathematics (2010 - No. 42)

Join SR

< PRS = 90^o(Angle in a semicircle)

< PRS = 55^o (Angle between a chord and a tangent = Angle in the alternate segment)

< PSR + < PRS + < RSP = 180^o

90v + 55^o + < RSp = 180^o

< RSP = 180^o - 145^o

= 35^o