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In \( \triangle ABC \), if \( \angle A = x ^{0}, \angle B =3 x ^{0} \) and \( \angle C = y ^{0} \). If \( 3 y -5 x =30 \), then \( \angle B = \) a) \( 60^{\circ} \) b) \( 45^{\circ} \) c) \( 30^{\circ} \) d) \( 90^{\circ} \). |
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Answer» Given: A = x, B = 3x, C = y ∴ Sum of △le = x + 3x + y 180 = 4x + y ⟹180−4x = y Also,3y − 5x = 30∘ Subtituting y value, ∴ 3(180−4x)−5x = 30 ∴ x = 30, by solving ∴ y = 180−4×30 = 60 ∴ A = 30∘; B = 90∘; C = 60∘ |
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