In the figure, ∠BDC = 90°. ∠BDE is 40° more than ∠CDE.
- What line is perpendicular to BD?
- Find ∠BDE.
(a)
Line CD or DC is perpendicular to BD.
(b)
∠CDE = 1 u
∠BDE = 1 u + 40
1 u + 1 u + 40° = 90° (Right angle)
2 u = 90° - 40° = 50°
1 u = 50° ÷ 2 = 25°
∠BDE
= 25° + 40°
= 65°
Answer(s): (a) CD or DC; (b) 65°