The figure, not drawn to scale, O is the centre of the circle and DJ // EH // FG. Find
- ∠COF
- ∠CHO
(a)
∠JOE
= 180° - 96°
= 84° (Interior angles, DJ//EO)
∠OFH = ∠OHF = 32° (Isosceles triangle)
∠EOF
= 32° + 32°
= 64° (Exterior angle of a triangle)
∠COF
= 84° + 64°
= 148°
(b)
∠HOF
= 180° - 32° -32°
= 116° (Isosceles triangle)
∠COH
= 360° - 148° - 116°
= 96° (Angles at a point)
CO = OH = Radius
∠CHO
= (180° - 96°) ÷ 2
= 84° ÷ 2
= 42° (Isosceles triangle)
Answer(s): (a) 148°; (b) 42°