In the figure, DE = DG, ∠EDG = 36° and ∠HFG = 12°. Find
- ∠c
- ∠d
(a)
∠DEG
= (180° - 36°) ÷ 2
= 72° (Isosceles triangle)
∠c
= 180° - 12° - 72°
= 96° (Angles sum of triangle)
(b)
∠DGF
= 180° - 72°
= 108° (Angles on a straight line)
∠d
= 12° + 108°
= 120° (Exterior angle of a triangle)
Answer(s): (a) 96°; (b) 120°