Quadrilateral abcd is inscribed in this circle.
what is the measure of angle b?

enter your answer in the box.
m∠b= °

Assuming the sum of the  opposite angle would be 180. We can easily calculate for x and ultimately solve for the angle of B. We do as follows

B + D = 180
3x-12 + x = 180
4x - 12 = 180
4x = 192
x = 48 degrees

Therefore angle B would have a measurement of 132 degrees. Hope this helps.

Yeah she/ he needs look how long that is man