The figure, not drawn to scale, O is the centre of the circle and BG // CF // DE. Find
- ∠AOD
- ∠AFO
(a)
∠GOC
= 180° - 94°
= 86° (Interior angles, BG//CO)
∠ODF = ∠OFD = 33° (Isosceles triangle)
∠COD
= 33° + 33°
= 66° (Exterior angle of a triangle)
∠AOD
= 86° + 66°
= 152°
(b)
∠FOD
= 180° - 33° -33°
= 114° (Isosceles triangle)
∠AOF
= 360° - 152° - 114°
= 94° (Angles at a point)
AO = OF = Radius
∠AFO
= (180° - 94°) ÷ 2
= 86° ÷ 2
= 43° (Isosceles triangle)
Answer(s): (a) 152°; (b) 43°