(i) From the given figure, ABCD is a quadrilateral
∠A+∠B+∠C+∠D=360∘(3x+4)+(50+x)+(5x+8)+(3x+10)=360∘3x+4+50+x+5x+8+3x+20=360∘12x+72=360∘
By transposing we get,
12x=360∘−7212x=288x=288/12x=24
(ii) ∠DAB=(3x+4)
=((3×24)+4)
=72+4=76∘
Therefore, ∠DAB=76∘
(iii) Consider the triangle ABD, We know that, sum of interior angles of triangle is equal to 180∘,
∠DAB+∠ABD+∠ADB=180∘76∘+50∘+∠ADB=180∘∠ADB+126∘=180∘∠ADB=180∘−126∘
Therefore, ∠ADB=54∘