In the figure, T is the centre of the circle, QT is parallel to RS and ∠RTS = 100°. Find the values of
- ∠g
- ∠h
- ∠i
(a)
∠g
= (180° - 100°) ÷ 2
= 40° (Angle properties within a circle)
(b)
∠QTR = ∠g = 40° (Alternate angles)
∠h
= (180° - 40°) ÷ 2
= 70° (Angle properties within a circle)
(c)
∠i
= 360° - 100° - 40°
= 220° (Angles at a point)
Answer(s): (a) 40°; (b) 70°; (c) 220°