# In aΔ ABC if 3 ∠A = 4∠B = 6∠C, then the value of ∠A =

Answered

(a) 60^{o}

(b) 80^{o}

(c) 30^{0}

(d) 40^{o}

Best answer

**Answer: (b) 80 ^{o}**

**Solution:-**

3ÐA = 4ÐB = 6ÐC (Given)

Then, ÐB = 3/4 ÐA & ÐC = 3/6 ÐA => ÐC = ÐA/2 ………………..(1)

As, we know that the sum of all angles of a triangle is 180^{o}.

Then, ÐA + ÐB + ÐC = 180^{o}

From equation (1),

ÐA + 3/4 ÐA + ÐA/2 = 180^{o}

(4 ÐA + 3 ÐA + 2 ÐA)/4 = 180^{o}

9 ÐA = 180 x 4

ÐA = 720/9

ÐA = 90^{o}

Then, the value of ÐA will be 80^{o}.

Hence, the correct answer is option (b) 80^{o}.