In a quadrilateral ABCD, ∠A=90∘, ∠B=3x, ∠C=3x+5, ∠D=8x−15.
Then, the value of ∠D is
The correct option is D 145∘
Since the sum of interior angles of a quadrilateral is 360∘
90+3x+3x+5+8x−15=36090+14x−10=36014x=360−80x=28014=20Then,∠D=8x−15
= 8(20)−15=145∘