Answer:
90deg
Step-by-step explanation:
If the angles are supplementary, that means mA + mB = 180*
we know that
mA = (2x + 8)deg
mB = (2x + 8)deg = mA
mA + mB = 180deg
mB + mB = 2mB = 180deg
mB = 90deg
Note, that we did not need to compute x even, because the angles were the same.
