B.
If m ZACB = 180°, and mZACD = 55°, then
mZDCB = [?]
Enter

Answer:
125
Step-by-step explanation:
/_ ACB = 180
/_ ACD = 55
/_ ACB is made up of /_ACD and
/_ DCB
Hence, /_ ACB = /_ ACD + /_ DCB
*We then plug in the known values*
180 = 55 + /_ DCB
We now solve for the missing angle
Subtract 55 from both sides
125 = /_ DCB