BD is the diagonal of parallelogram ABCD such that ∠CBD = 12x, ∠ABD = 7y, ∠ADB = 60° and ∠CDB = 28°. Then, the value of 2x + 3y is :किसी समांतर चतुर्भुज ABCD का विकर्ण BD इस प्रकार है कि ∠CBD = 12x, ∠ABD = 7y, ∠ADB = 60° और ∠CDB = 28° है। तब 2x + 3y का मान है :

Explanation

In a parallelogram AD ∥ BC and AB ∥ DC, so alternate angles give ∠CBD = ∠ADB: 12x = 60, x = 5; and ∠ABD = ∠CDB: 7y = 28, y = 4. Hence 2x + 3y = 10 + 12 = 22.समांतर चतुर्भुज में AD ∥ BC और AB ∥ DC होता है, इसलिए एकांतर कोणों से ∠CBD = ∠ADB: 12x = 60, x = 5; तथा ∠ABD = ∠CDB: 7y = 28, y = 4। अतः 2x + 3y = 10 + 12 = 22।