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प्रश्न
Choose the correct alternative:
In ∆ABC, AB = `6sqrt(3)` cm, AC = 12 cm, and BC = 6 cm, then m∠A = ?
विकल्प
30°
60°
90°
45°
उत्तर
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)
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