ABCD is a cyclic quadrilateral in which angle B is opposite to angle D. If ∠B = x + 10 degree and ∠D = 2x + 35 degree, then what is the value of x ?

45 degree

Since \(\angle\)B and \(\angle\)D are opposite to each other, we have,

\(\angle\)B + \(\angle\)D = 180

= x + 10 + 2x + 35 = 180

Solving for x

= 3x + 45 = 180

= 3x = 135

= x = 45

Therefore, x is \({45}^\circ\).