Q71
In a triangle ABC, ∠A = 90°, ∠C = 55°, AD ⊥ BC . What is the value of ∠BAD ?
In a triangle ABC, ∠A = 90°, ∠C = 55°, ⊥ . What is the value of ∠BAD ?
A.
35°
B.
60°
C.
45°
D.
55°
AnswerAnswer: Option D
Solution
Answer: Option D
Solution:
According to question,
In right angle ΔBAC
∠A + ∠B + ∠C = 180°
∠B = 180° - 55° - 90°
∠B = 35°
In right angle ΔADB
∠ADB + ∠ABD + ∠BAD = 180°
∠BAD = 180° - 35° - 90°
∠BAD = 55°
Alternate
ΔBAC ∼ ΔBDA
∴ ∠BCA = ∠BAD = 55°