The figure is not drawn to scale. ZA//CB and BA//DZ. Triangles ZDA and ABC are isosceles triangles. Find
- ∠e
- ∠f.
(a)
∠ABC = ∠AZD = 74° (BA//DZ, AZ//BC)
∠ZAD
= (180° - 74°) ÷ 2
= 106° ÷ 2
= 53° (Isosceles triangle)
∠BAC
= 180° - 74° - 74°
= 32° (Isosceles triangle)
∠e
= 180° - 74° - 53° - 32°
= 21° (Interior angles, AZ//BC)
(b)
∠f
= 180° - 29° - 21°
= 130° (Angles sum of triangle)
Answer(s): (a) 21°; (b) 130°