PSLE In the figure, CDF and HGF are straight lines and GD is parallel to FE. ∠GHC is a right angle, ∠HCD = 48°, ∠CDE = 124° and ∠FGD = 68°.
- Find ∠CDG.
- Find ∠DEF.
(a)
∠CFH
= 180° - 90° - 48°
= 42° (Angles sum of triangle)
∠FDG
= 180° - 68° - 42°
= 70° (Angles sum of triangle)
∠CDG
= 180° - 70°
= 124° (Angles on a straight line)
(b)
∠FDE
= 360° - 124° - 70° - 124°
= 42° (Angles at a point)
∠DEF
= 180° - 42° - 42°
= 96°
Answer(s): (a) 124°; (b) 96°