In the figure, CDF and HGlE are straight lines. ∠CHG = 48°, ∠HCG = 43°, ∠DEF = 31° and ∠DFE = 117°. Find
- ∠CGD
- ∠GCD
(a)
∠CGH
= 180° - 43° - 48°
= 89° (Angles sum of triangle)
∠CGD
= 180° - 89°
= 91° (Angles on a straight line)
(b)
∠FDE
= 180° - 117° - 31°
= 32° (Angles sum of triangle)
∠CDG = ∠FDE = 32° (Vertically opposite angles)
∠GCD
= 180° - 91° - 32°
= 57° (Angles sum of triangle)
Answer(s): (a) 91°; (b) 57°