C-06-Q185mediumsingle_mcqIn △ABC\triangle ABC△ABC, ∠C=1\angle C = 1∠C=1 right angle and ∠B=2∠A\angle B = 2 \angle A∠B=2∠A. Then ∠A=\angle A =∠A=a30°30°30°b45°45°45°c60°60°60°d90°90°90°ব্যাখ্যাThe angles sum to 180°180°180°, so ∠A+2∠A+90°=180°\angle A + 2\angle A + 90° = 180°∠A+2∠A+90°=180°, giving 3∠A=90°3\angle A = 90°3∠A=90°. Thus ∠A=30°\angle A = 30°∠A=30°.