To solve this problem, we must remember that a straight line has a value of 180 degrees. This means that the two angles shown above, b and 48 degrees, are supplementary, because their sum is 180 degrees. With this knowledge, we can create an equation, modeled below:
b + 48 = 180
To solve this equation, we must get the variable b alone on the left side of the equation, so we should subtract 48 from both sides of the equation.
b = 132
Therefore, your answer is angle b measures 132 degrees.
Hope this helps!