In the figure, YZAB is a parallelogram. AD, DE and YZ are straight lines. YBC is an isosceles triangle.
- Find ∠d.
- Find ∠e.
(a)
∠ADY = ∠ZYE = 61° (Corresponding angles, YZ//DA)
∠DCY
= 180° - ∠ADY - ∠DYC
= 180° - 61° - 19°
= 100° (Angles sum of triangle)
∠BCY
= 180° - 100°
= 80° (Angles on a straight line)
∠CBY = ∠BCY = 80° (Isosceles triangle)
∠d
= ∠CBY
= 80° (Corresponding angles, ZA//YB)
(b)
∠e
= 180° - 80° - 80°
= 20° (Isosceles triangle YBC)
Answer(s): (a) 80°; (b) 20°