Question

O is the center of the circle. Angle AOB=40
FIND X and Y

Answer 1

angle AOB = 40°
SO,

ANGLE AT CENTRE IS 40°

JOIN AB

THEN,

BY TAKING AB AS A COMMON CHORD FOR ANGLES AOB AND ACB

X = (40°)/2 [ANGLE AT CENTRE IS TWICE THE ANGLE AT CIRCUMFERENCE FROM THE SAME CHORD)]

X= 20°
Y=20°

Answer 2

DOB = COA = 180- 40 = 140
Since OC = OA
OCA = OAC = x
In ∆ OAC
OCA + OAC + COA = 180°
So 2x + 140 = 180°
or x = 20°
Similarly y = 20°