In a ΔABC its is given that ∠A : ∠B : ∠C = 3 : 2 : 1 and CD ⊥ AC. Then ∠ECD = ?
As per question,
So,
∠A = 90o
∠B = 60o
∠C = 30o
∠ACB + ∠ACD + ∠ECD = 180o (sum of angles on straight line)
∠ECD = 180o – 90o – 30o
= 60o