PSLEIn the figure, ZABC is a parallelogram. ZXC and XBY are straight lines. ∠YBC = 150°, ∠ZCB = 42° and ∠ZBX = 17°.
- Find ∠ABY.
- Find ∠AZB.
(a)
∠ABC
= 180° - 42°
= 138° (Interior angles)
∠ABY
= 360° - 150° - 138°
= 72° (Angles at a point)
(b)
∠CBX
= 180° - 150°
= 30°(Angles on a straight line)
∠AZB
= ∠ZBC
= 30° + 17°
= 47° (Alternate angles)
Answer(s): (a) 72°; (b) 47°