Answer:
132°
Step-by-step explanation:
We use the circle theorem which states that :
Opposite angles in a cyclic quadrilateral add up to 180 .
Now we know that angles ADC and ABC add up to 180. So :
We make an equation and solve for x :
x+(3x-12) = 180
4x-12 = 180
4x = 192
x = 48
Now we substitute the value of x into Angle B :
3(48) -12 =
144 - 12 = 132
Angle B = 132 °
Hope this helped and have a good day
