In the figure, AB = AD, ∠BAD = 32° and ∠ECD = 17°. Find
- ∠m
- ∠n
(a)
∠ABD
= (180° - 32°) ÷ 2
= 74° (Isosceles triangle)
∠m
= 180° - 17° - 74°
= 89° (Angles sum of triangle)
(b)
∠ADC
= 180° - 74°
= 106° (Angles on a straight line)
∠n
= 17° + 106°
= 123° (Exterior angle of a triangle)
Answer(s): (a) 89°; (b) 123°