Question

Choose the correct alternative:

In ∆ABC, AB = `6sqrt(3)` cm, AC = 12 cm, and BC = 6 cm, then m∠A = ?

Options

• 30°

• 60°

• 90°

• 45°

Answer 1

30°

We know that, 6 = `1/2`(12) and 

`6sqrt3 = sqrt3/2 (12)`

∴ BC = `1/2 "AC and AB" = sqrt3/2 "AC"` 

∴ ∠A = 30°   ...(Converse of 30°-60°-90° theorem)