The figure, not drawn to scale, O is the centre of the circle and GM // HL // JK. Find
- ∠FOJ
- ∠FLO
(a)
∠MOH
= 180° - 100°
= 80° (Interior angles, GM//HO)
∠OJL = ∠OLJ = 31° (Isosceles triangle)
∠HOJ
= 31° + 31°
= 62° (Exterior angle of a triangle)
∠FOJ
= 80° + 62°
= 142°
(b)
∠LOJ
= 180° - 31° -31°
= 118° (Isosceles triangle)
∠FOL
= 360° - 142° - 118°
= 100° (Angles at a point)
FO = OL = Radius
∠FLO
= (180° - 100°) ÷ 2
= 80° ÷ 2
= 40° (Isosceles triangle)
Answer(s): (a) 142°; (b) 40°
