PSLE In the figure, CDF and HGF are straight lines and GD is parallel to FE. ∠GHC is a right angle, ∠HCD = 50°, ∠CDE = 114° and ∠FGD = 66°.
- Find ∠CDG.
- Find ∠DEF.
(a)
∠CFH
= 180° - 90° - 50°
= 40° (Angles sum of triangle)
∠FDG
= 180° - 66° - 40°
= 74° (Angles sum of triangle)
∠CDG
= 180° - 74°
= 114° (Angles on a straight line)
(b)
∠FDE
= 360° - 114° - 74° - 114°
= 58° (Angles at a point)
∠DEF
= 180° - 58° - 58°
= 64°
Answer(s): (a) 114°; (b) 64°