In the figure, ABE and DBC are right-angled triangles. EB is parallel to DC. Find
- ∠BCD
- ∠BED
(a)
∠DBE
= 360° - 90° - 90° - 123°
= 57° (Angles at a point)
∠BDC = ∠DBE = 57° (Alternate angles)
∠BCD
= 180° - ∠DBC - ∠BDC
= 180° - 90° - 57°
= 33° (Angles sum of triangle)
(b)
∠BED
= 180° - ∠DBE - ∠BDE
= 180° - 57° - 87°
= 36° (Angles sum of triangle)
Answer(s): (a) 33°; (b) 36°