In the figure, ∠ACB = 90°. ∠ACD is 39° more than ∠BCD.
- What line is perpendicular to AC?
- Find ∠ACD.
(a)
Line BC or CB is perpendicular to AC.
(b)
∠BCD = 1 u
∠ACD = 1 u + 39
1 u + 1 u + 39° = 90° (Right angle)
2 u = 90° - 39° = 51°
1 u = 51° ÷ 2 = 25.5°
∠ACD
= 25.5° + 39°
= 64.5°
Answer(s): (a) BC or CB; (b) 64.5°