In the figure, CDG and FDE are right-angled triangles. GD is parallel to FE. Find
- ∠DEF
- ∠DGF
(a)
∠FDG
= 360° - 90° - 90° - 123°
= 57° (Angles at a point)
∠DFE = ∠FDG = 57° (Alternate angles)
∠DEF
= 180° - ∠FDE - ∠DFE
= 180° - 90° - 57°
= 33° (Angles sum of triangle)
(b)
∠DGF
= 180° - ∠FDG - ∠DFG
= 180° - 57° - 85°
= 38° (Angles sum of triangle)
Answer(s): (a) 33°; (b) 38°
