The figure is not drawn to scale. XZAB is a trapezium and XZ // BA. Given that XB = XY, ∠BXY = 79° and ∠XZA = 98°.
- Find ∠ZAB
- Find ∠XYB
- Find ∠YBA
(a)
∠ZAB
= 180° - 98°
= 82° (Interior angles, XZ//BA)
(b)
∠XYB
= (180° - 79°) ÷ 2
= 101° ÷ 2
= 50.5° (Isosceles triangle)
(c)
∠YBA
= ∠XYB
= 50.5° (Alternate angles, XZ//BA)
Answer(s): (a) 82°; (b) 50.5°; (c) 50.5°