The figure, not drawn to scale, O is the centre of the circle and XC // YB // ZA. Find
- ∠WOZ
- ∠WBO
(a)
∠COY
= 180° - 100°
= 80° (Interior angles, XC//YO)
∠OZB = ∠OBZ = 32° (Isosceles triangle)
∠YOZ
= 32° + 32°
= 64° (Exterior angle of a triangle)
∠WOZ
= 80° + 64°
= 144°
(b)
∠BOZ
= 180° - 32° -32°
= 116° (Isosceles triangle)
∠WOB
= 360° - 144° - 116°
= 100° (Angles at a point)
WO = OB = Radius
∠WBO
= (180° - 100°) ÷ 2
= 80° ÷ 2
= 40° (Isosceles triangle)
Answer(s): (a) 144°; (b) 40°