Question

,determine the value of y

Answer 1

Angle COD and angle EOI are equal angles (opposite interior angles) 
So, Angle COD = angle EOI = 5y
AB is a straight line, So central angle = 180 degrees
angle COB+angle DOA+angle COD = 180 degrees
5y+5y+2y=180
12y = 180
y = 180/5
y = 15 degrees

Answer 2

Angle EOF = angle COD=5y( V.O.A ) Also, Angle AOD= Angle BOE=2y( V.O.A. ) Angle BOC= Angle AOF= 5y ( V.O.A. ) 5y+5y+5y+5y+2y+2y=360 ( sum of angles on a point is 360° ), Therefore, 24y=360° y=360°/24=15 y=15