Here, given that,
∠A=90∘∠B=(2x+4)∘∠C=(3x−5)∘∠D=(8x−15)∘
We know that,
Sum of all the interior angles in a quadrilateral is 360∘
So,
∠A+∠B+∠C+∠D=360∘
90∘+(2x+4∘)+(3x−5∘)+(8x−15∘)=360∘
On further calculation, we get
90∘+2x+4∘+3x−5∘+8x−15∘=360∘74∘+13x=360∘13x=360∘−74∘13x=286∘x=(28613)∘We get,x=22∘The value of x is 22∘Now,∠B=2x+4∘=2×22∘+4∘=48∘∠C=3x−5∘=3×22∘−5∘=61∘
Therefore, ∠B=48∘ and ∠C=61∘