The altitude AD of a triangle ABC is 9cm. If AB = 6 √(3) cm and CD = 3 √(3) cm, then what will be the measure of ∠A?

The altitude AD of a triangle ABC is 9cm. If AB = 6 √(3)…

The altitude AD of a triangle ABC is 9cm. If AB = 6 $\sqrt{3}$ cm and CD = 3 $\sqrt{3}$ cm, then what will be the measure of ∠A?

Show answer & explanation

Correct answer: D

Explanation

The correct answer is option 4 i.e. 60º

(6√3)² = (BD)² + 9²

⇒ BD = 3√3 cm

∵ DC = BD = 3√3 cm

∴ BC = AC = AB = 6√3 cm &

∠A = ∠B = ∠C = 60°

ABC is an equilateral triangle.