The figure, not drawn to scale, O is the centre of the circle and PU // QT // RS. Find
- ∠NOR
- ∠NTO
(a)
∠UOQ
= 180° - 100°
= 80° (Interior angles, PU//QO)
∠ORT = ∠OTR = 32° (Isosceles triangle)
∠QOR
= 32° + 32°
= 64° (Exterior angle of a triangle)
∠NOR
= 80° + 64°
= 144°
(b)
∠TOR
= 180° - 32° -32°
= 116° (Isosceles triangle)
∠NOT
= 360° - 144° - 116°
= 100° (Angles at a point)
NO = OT = Radius
∠NTO
= (180° - 100°) ÷ 2
= 80° ÷ 2
= 40° (Isosceles triangle)
Answer(s): (a) 144°; (b) 40°