WAEC - Mathematics (2006 - No. 38)

Draw a line from P to Q

< PQS = < PRS (angle in the sam segment)

< PQS = 50^o

Also, < QSR = < QPR(angles in the segment)

< QPR = x^o

x + y + 5= = 180(angles in a triangle)

x + y = 180 - 50

x + y = 130^o