The figure, not drawn to scale, O is the centre of the circle and GM // HL // JK. Find
- ∠FOJ
- ∠FLO
(a)
∠MOH
= 180° - 102°
= 78° (Interior angles, GM//HO)
∠OJL = ∠OLJ = 30° (Isosceles triangle)
∠HOJ
= 30° + 30°
= 60° (Exterior angle of a triangle)
∠FOJ
= 78° + 60°
= 138°
(b)
∠LOJ
= 180° - 30° -30°
= 120° (Isosceles triangle)
∠FOL
= 360° - 138° - 120°
= 102° (Angles at a point)
FO = OL = Radius
∠FLO
= (180° - 102°) ÷ 2
= 78° ÷ 2
= 39° (Isosceles triangle)
Answer(s): (a) 138°; (b) 39°